WebSVN – SvarDOS – Diff – /svarcom/trunk/command.c


/* This file is part of the SvarCOM project and is published under the terms
 * of the MIT license.
 *
 * Copyright (C) 2021-2022 Mateusz Viste
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 */
 
#include <i86.h>
#include <dos.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
 
#include <process.h>
 
#include "cmd.h"
#include "env.h"
#include "helpers.h"
#include "redir.h"
#include "rmodinit.h"
#include "sayonara.h"
 
#include "rmodcore.h" /* rmod binary inside a BUFFER array */
 
/* this version byte is used to tag RMOD so I can easily make sure that
 * the RMOD struct I find in memory is one that I know. Should the version
 * mismatch, then it would likely mean that SvarCOM has been upgraded and
 * RMOD should not be accessed as its structure might no longer be in sync
 * with what I think it is.
 *          *** INCREMENT THIS AT EACH NEW SVARCOM RELEASE! ***          */
#define BYTE_VERSION 3
 
 
struct config {
  unsigned char flags; /* command.com flags, as defined in rmodinit.h */
  char *execcmd;
  unsigned short envsiz;
};
 
/* max length of the cmdline storage (bytes) - includes also max length of
 * line loaded from a BAT file (no more than 255 bytes!) */
#define CMDLINE_MAXLEN 255
 
 
/* sets guard values at a few places in memory for later detection of
 * overflows via memguard_check() */
static void memguard_set(char *cmdlinebuf) {
  BUFFER[sizeof(BUFFER) - 1] = 0xC7;
  cmdlinebuf[CMDLINE_MAXLEN] = 0xC7;
}
 
 
/* checks for valguards at specific memory locations, returns 0 on success */
static int memguard_check(unsigned short rmodseg, char *cmdlinebuf) {
  /* check RMOD signature (would be overwritten in case of stack overflow */
  static char msg[] = "!! MEMORY CORRUPTION ## DETECTED !!";
  unsigned short far *rmodsig = MK_FP(rmodseg, 0x100 + 6);
  unsigned char far *rmod = MK_FP(rmodseg, 0);
 
  if (*rmodsig != 0x2019) {
    msg[22] = '1';
    goto FAIL;
  }
 
  /* check last BUFFER byte */
  if (BUFFER[sizeof(BUFFER) - 1] != 0xC7) {
    msg[22] = '2';
    goto FAIL;
  }
 
  /* check last cmdlinebuf byte */
  if (cmdlinebuf[CMDLINE_MAXLEN] != 0xC7) {
    msg[22] = '3';
    goto FAIL;
  }
 
  /* check rmod exec buf */
  if (rmod[RMOD_OFFSET_EXECPROG + 127] != 0) {
    msg[22] = '4';
    goto FAIL;
  }
 
  /* check rmod exec stdin buf */
  if (rmod[RMOD_OFFSET_STDINFILE + 127] != 0) {
    msg[22] = '5';
    goto FAIL;
  }
 
  /* check rmod exec stdout buf */
  if (rmod[RMOD_OFFSET_STDOUTFILE + 127] != 0) {
    msg[22] = '6';
    goto FAIL;
  }
 
  /* else all good */
  return(0);
 
  /* error handling */
  FAIL:
  outputnl(msg);
  return(1);
}
 
 
/* parses command line the hard way (directly from PSP) */
static void parse_argv(struct config *cfg) {
  const unsigned char *cmdlinelen = (void *)0x80;
  char *cmdline = (void *)0x81;
 
  memset(cfg, 0, sizeof(*cfg));
 
  /* set a NULL terminator on cmdline */
  cmdline[*cmdlinelen] = 0;
 
  while (*cmdline != 0) {
 
    /* skip over any leading spaces */
    if (*cmdline == ' ') {
      cmdline++;
      continue;
    }
 
    if (*cmdline != '/') {
      output("Invalid parameter: ");
      outputnl(cmdline);
      goto SKIP_TO_NEXT_ARG;
    }
 
    /* got a slash */
    cmdline++;  /* skip the slash */
    switch (*cmdline) {
      case 'c': /* /C = execute command and quit */
      case 'C':
        cfg->flags |= FLAG_EXEC_AND_QUIT;
        /* FALLTHRU */
      case 'k': /* /K = execute command and keep running */
      case 'K':
        cfg->execcmd = cmdline + 1;
        return;
 
      case 'd': /* /D = skip autoexec.bat processing */
      case 'D':
        cfg->flags |= FLAG_SKIP_AUTOEXEC;
        break;
 
      case 'e': /* preset the initial size of the environment block */
      case 'E':
        cmdline++;
        if (*cmdline == ':') cmdline++; /* could be /E:size */
        atous(&(cfg->envsiz), cmdline);
        if (cfg->envsiz < 64) cfg->envsiz = 0;
        break;
 
      case 'p': /* permanent shell (can't exit + run autoexec.bat) */
      case 'P':
        cfg->flags |= FLAG_PERMANENT;
        break;
 
      case '?':
        outputnl("Starts the SvarCOM command interpreter");
        outputnl("");
        outputnl("COMMAND /E:nnn [/[C|K] [/P] [/D] command]");
        outputnl("");
        outputnl("/D      Skip AUTOEXEC.BAT processing (makes sense only with /P)");
        outputnl("/E:nnn  Sets the environment size to nnn bytes");
        outputnl("/P      Makes the new command interpreter permanent and run AUTOEXEC.BAT");
        outputnl("/C      Executes the specified command and returns");
        outputnl("/K      Executes the specified command and continues running");
        exit(1);
        break;
 
      default:
        output("Invalid switch: /");
        outputnl(cmdline);
        break;
    }
 
    /* move to next argument or quit processing if end of cmdline */
    SKIP_TO_NEXT_ARG:
    while ((*cmdline != 0) && (*cmdline != ' ') && (*cmdline != '/')) cmdline++;
  }
}
 
 
/* builds the prompt string and displays it. buff is filled with a zero-terminated copy of the prompt. */
static void build_and_display_prompt(char *buff, unsigned short envseg) {
  char *s = buff;
  /* locate the prompt variable or use the default pattern */
  const char far *fmt = env_lookup_val(envseg, "PROMPT");
  if ((fmt == NULL) || (*fmt == 0)) fmt = "$p$g"; /* fallback to default if empty */
  /* build the prompt string based on pattern */
  for (; *fmt != 0; fmt++) {
    if (*fmt != '$') {
      *s = *fmt;
      s++;
      continue;
    }
    /* escape code ($P, etc) */
    fmt++;
    switch (*fmt) {
      case 'Q':  /* $Q = = (equal sign) */
      case 'q':
        *s = '=';
        s++;
        break;
      case '$':  /* $$ = $ (dollar sign) */
        *s = '$';
        s++;
        break;
      case 'T':  /* $t = current time */
      case 't':
        s += sprintf(s, "00:00"); /* TODO */
        break;
      case 'D':  /* $D = current date */
      case 'd':
        s += sprintf(s, "1985-07-29"); /* TODO */
        break;
      case 'P':  /* $P = current drive and path */
      case 'p':
        _asm {
          mov ah, 0x19    /* DOS 1+ - GET CURRENT DRIVE */
          int 0x21
          mov bx, s
          mov [bx], al  /* AL = drive (00 = A:, 01 = B:, etc */
        }
        *s += 'A';
        s++;
        *s = ':';
        s++;
        *s = '\\';
        s++;
        _asm {
          mov ah, 0x47    /* DOS 2+ - CWD - GET CURRENT DIRECTORY */
          xor dl,dl       /* DL = drive number (00h = default, 01h = A:, etc) */
          mov si, s       /* DS:SI -> 64-byte buffer for ASCIZ pathname */
          int 0x21
          jc DONE         /* leave path empty on error */
          /* move s ptr forward to end (0-termintor) of pathname */
          NEXTBYTE:
          mov si, s
          cmp byte ptr [si], 0
          je DONE
          inc s
          jmp NEXTBYTE
          DONE:
        }
        break;
      case 'V':  /* $V = DOS version number */
      case 'v':
        s += sprintf(s, "VER"); /* TODO */
        break;
      case 'N':  /* $N = current drive */
      case 'n':
        _asm {
          mov ah, 0x19    /* DOS 1+ - GET CURRENT DRIVE */
          int 0x21
          mov bx, s
          mov [bx], al  /* AL = drive (00 = A:, 01 = B:, etc */
        }
        *s += 'A';
        s++;
        break;
      case 'G':  /* $G = > (greater-than sign) */
      case 'g':
        *s = '>';
        s++;
        break;
      case 'L':  /* $L = < (less-than sign) */
      case 'l':
        *s = '<';
        s++;
        break;
      case 'B':  /* $B = | (pipe) */
      case 'b':
        *s = '|';
        s++;
        break;
      case 'H':  /* $H = backspace (erases previous character) */
      case 'h':
        *s = '\b';
        s++;
        break;
      case 'E':  /* $E = Escape code (ASCII 27) */
      case 'e':
        *s = 27;
        s++;
        break;
      case '_':  /* $_ = CR+LF */
        *s = '\r';
        s++;
        *s = '\n';
        s++;
        break;
    }
  }
  *s = 0;
  output(buff);
}
 
 
/* a few internal flags */
#define DELETE_STDIN_FILE 1
#define CALL_FLAG         2
 
static void run_as_external(char *buff, const char *cmdline, unsigned short envseg, struct rmod_props far *rmod, struct redir_data *redir, unsigned char flags) {
  char *cmdfile = buff + 512;
  const char far *pathptr;
  int lookup;
  unsigned short i;
  const char *ext;
  char *cmd = buff + 1024;
  const char *cmdtail;
  char far *rmod_execprog = MK_FP(rmod->rmodseg, RMOD_OFFSET_EXECPROG);
  char far *rmod_cmdtail = MK_FP(rmod->rmodseg, 0x81);
  _Packed struct {
    unsigned short envseg;
    unsigned long cmdtail;
    unsigned long fcb1;
    unsigned long fcb2;
  } far *ExecParam = MK_FP(rmod->rmodseg, RMOD_OFFSET_EXECPARAM);
 
  /* find cmd and cmdtail */
  i = 0;
  cmdtail = cmdline;
  while (*cmdtail == ' ') cmdtail++; /* skip any leading spaces */
  while ((*cmdtail != ' ') && (*cmdtail != '/') && (*cmdtail != '+') && (*cmdtail != 0)) {
    cmd[i++] = *cmdtail;
    cmdtail++;
  }
  cmd[i] = 0;
 
  /* is this a command in curdir? */
  lookup = lookup_cmd(cmdfile, cmd, NULL, &ext);
  if (lookup == 0) {
    /* printf("FOUND LOCAL EXEC FILE: '%s'\r\n", cmdfile); */
    goto RUNCMDFILE;
  } else if (lookup == -2) {
    /* puts("NOT FOUND"); */
    return;
  }
 
  /* try matching something in PATH */
  pathptr = env_lookup_val(envseg, "PATH");
 
  /* try each path in %PATH% */
  while (pathptr) {
    for (i = 0;; i++) {
      buff[i] = *pathptr;
      if ((buff[i] == 0) || (buff[i] == ';')) break;
      pathptr++;
    }
    buff[i] = 0;
    lookup = lookup_cmd(cmdfile, cmd, buff, &ext);
    if (lookup == 0) goto RUNCMDFILE;
    if (lookup == -2) return;
    if (*pathptr == ';') {
      pathptr++;
    } else {
      break;
    }
  }
 
  /* last chance: is it an executable link? (trim extension from cmd first) */
  for (i = 0; (cmd[i] != 0) && (cmd[i] != '.') && (i < 9); i++) buff[128 + i] = cmd[i];
  buff[128 + i] = 0;
  if ((i < 9) && (link_computefname(buff, buff + 128, envseg) == 0)) {
    /* try opening the link file (if it exists) and read it into buff */
    i = 0;
    _asm {
      push ax
      push bx
      push cx
      push dx
 
      mov ax, 0x3d00  /* DOS 2+ - OPEN EXISTING FILE, READ-ONLY */
      mov dx, buff    /* file name */
      int 0x21
      jc ERR_FOPEN
      /* file handle in AX, read from file now */
      mov bx, ax      /* file handle */
      mov ah, 0x3f    /* Read from file via handle bx */
      mov cx, 128     /* up to 128 bytes */
      /* mov dx, buff */ /* dest buffer (already set) */
      int 0x21        /* read up to 256 bytes from file and write to buff */
      jc ERR_READ
      mov i, ax
      ERR_READ:
      mov ah, 0x3e    /* close file handle in BX */
      int 0x21
      ERR_FOPEN:
 
      pop dx
      pop cx
      pop bx
      pop ax
    }
 
    /* did I read anything? */
    if (i != 0) {
      buff[i] = 0;
      /* trim buff at first \n or \r, just in case someone fiddled with the
       * link file using a text editor */
      for (i = 0; (buff[i] != 0) && (buff[i] != '\r') && (buff[i] != '\n'); i++);
      buff[i] = 0;
      /* lookup check */
      if (buff[0] != 0) {
        lookup = lookup_cmd(cmdfile, cmd, buff, &ext);
        if (lookup == 0) goto RUNCMDFILE;
      }
    }
  }
 
  /* all failed (ie. executable file not found) */
  return;
 
  RUNCMDFILE:
 
  /* special handling of batch files */
  if ((ext != NULL) && (imatch(ext, "bat"))) {
    struct batctx far *newbat;
 
    /* remember the echo flag (in case bat file disables echo, only when starting first bat) */
    if (rmod->bat == NULL) {
      rmod->flags &= ~FLAG_ECHO_BEFORE_BAT;
      if (rmod->flags & FLAG_ECHOFLAG) rmod->flags |= FLAG_ECHO_BEFORE_BAT;
    }
 
    /* if bat is not called via a CALL, then free the bat-context linked list */
    if ((flags & CALL_FLAG) == 0) rmod_free_bat_llist(rmod);
 
 
 
 
 
 
    /* allocate a new bat context */
    newbat = rmod_fcalloc(sizeof(struct batctx), rmod->rmodseg, "SVBATCTX");
    if (newbat == NULL) {
      nls_outputnl_doserr(8); /* insufficient memory */
      return;
    }
 
    /* fill the newly allocated batctx structure */
    _fstrcpy(newbat->fname, cmdfile); /* truename of the BAT file */
    /* explode args of the bat file and store them in rmod buff */
    cmd_explode(buff, cmdline, NULL);
    _fmemcpy(newbat->argv, buff, sizeof(newbat->argv));
 
    /* push the new bat to the top of rmod's linked list */
    newbat->parent = rmod->bat;
    rmod->bat = newbat;
 
    return;
  }
 
  /* copy full filename to execute, along with redirected files (if any) */
  _fstrcpy(rmod_execprog, cmdfile);
 
  /* copy stdin file if a redirection is needed */
  if (redir->stdinfile) {
    char far *farptr = MK_FP(rmod->rmodseg, RMOD_OFFSET_STDINFILE);
    char far *delstdin = MK_FP(rmod->rmodseg, RMOD_OFFSET_STDIN_DEL);
    _fstrcpy(farptr, redir->stdinfile);
    if (flags & DELETE_STDIN_FILE) {
      *delstdin = redir->stdinfile[0];
    } else {
      *delstdin = 0;
    }
  }
 
  /* same for stdout file */
  if (redir->stdoutfile) {
    char far *farptr = MK_FP(rmod->rmodseg, RMOD_OFFSET_STDOUTFILE);
    unsigned short far *farptr16 = MK_FP(rmod->rmodseg, RMOD_OFFSET_STDOUTAPP);
    _fstrcpy(farptr, redir->stdoutfile);
    /* openflag */
    *farptr16 = redir->stdout_openflag;
  }
 
  /* copy cmdtail to rmod's PSP and compute its len */
  for (i = 0; cmdtail[i] != 0; i++) rmod_cmdtail[i] = cmdtail[i];
  rmod_cmdtail[i] = '\r';
  rmod_cmdtail[-1] = i;
 
  /* set up rmod to execute the command */
 
  ExecParam->envseg = envseg;
  ExecParam->cmdtail = (unsigned long)MK_FP(rmod->rmodseg, 0x80); /* farptr, must be in PSP format (lenbyte args \r) */
  ExecParam->fcb1 = 0; /* TODO farptr */
  ExecParam->fcb2 = 0; /* TODO farptr */
  exit(0); /* let rmod do the job now */
}
 
 
static void set_comspec_to_self(unsigned short envseg) {
  unsigned short *psp_envseg = (void *)(0x2c); /* pointer to my env segment field in the PSP */
  char far *myenv = MK_FP(*psp_envseg, 0);
  unsigned short varcount;
  char buff[256] = "COMSPEC=";
  char *buffptr = buff + 8;
  /* who am i? look into my own environment, at the end of it should be my EXEPATH string */
  while (*myenv != 0) {
    /* consume a NULL-terminated string */
    while (*myenv != 0) myenv++;
    /* move to next string */
    myenv++;
  }
  /* get next word, if 1 then EXEPATH follows */
  myenv++;
  varcount = *myenv;
  myenv++;
  varcount |= (*myenv << 8);
  myenv++;
  if (varcount != 1) return; /* NO EXEPATH FOUND */
  while (*myenv != 0) {
    *buffptr = *myenv;
    buffptr++;
    myenv++;
  }
  *buffptr = 0;
  /* printf("EXEPATH: '%s'\r\n", buff); */
  env_setvar(envseg, buff);
}
 
 
/* wait for user input */
static void cmdline_getinput(unsigned short inpseg, unsigned short inpoff) {
  _asm {
    push ax
    push bx
    push cx
    push dx
    push ds
 
    /* is DOSKEY support present? (INT 2Fh, AX=4800h, returns non-zero in AL if present) */
    mov ax, 0x4800
    int 0x2f
    mov bl, al /* save doskey status in BL */
 
    /* set up buffered input to inpseg:inpoff */
    mov ax, inpseg
    push ax
    pop ds
    mov dx, inpoff
 
    /* execute either DOS input or DOSKEY */
    test bl, bl /* zf set if no DOSKEY present */
    jnz DOSKEY
 
    mov ah, 0x0a
    int 0x21
    jmp short DONE
 
    DOSKEY:
    mov ax, 0x4810
    int 0x2f
 
    DONE:
    /* terminate command with a CR/LF */
    mov ah, 0x02 /* display character in dl */
    mov dl, 0x0d
    int 0x21
    mov dl, 0x0a
    int 0x21
 
    pop ds
    pop dx
    pop cx
    pop bx
    pop ax
  }
}
 
 
/* fetches a line from batch file and write it to buff (NULL-terminated),
 * increments rmod counter and returns 0 on success. */
static int getbatcmd(char *buff, unsigned char buffmaxlen, struct rmod_props far *rmod) {
  unsigned short i;
  unsigned short batname_seg = FP_SEG(rmod->bat->fname);
  unsigned short batname_off = FP_OFF(rmod->bat->fname);
  unsigned short filepos_cx = rmod->bat->nextline >> 16;
  unsigned short filepos_dx = rmod->bat->nextline & 0xffff;
  unsigned char blen = 0;
  unsigned short errv = 0;
 
  /* open file, jump to offset filpos, and read data into buff.
   * result in blen (unchanged if EOF or failure). */
  _asm {
    push ax
    push bx
    push cx
    push dx
 
    /* open file (read-only) */
    mov bx, 0xffff        /* preset BX to 0xffff to detect error conditions */
    mov dx, batname_off
    mov ax, batname_seg
    push ds     /* save DS */
    mov ds, ax
    mov ax, 0x3d00
    int 0x21    /* handle in ax on success */
    pop ds      /* restore DS */
    jc ERR
    mov bx, ax  /* save handle to bx */
 
    /* jump to file offset CX:DX */
    mov ax, 0x4200
    mov cx, filepos_cx
    mov dx, filepos_dx
    int 0x21  /* CF clear on success, DX:AX set to cur pos */
    jc ERR
 
    /* read the line into buff */
    mov ah, 0x3f
    xor ch, ch
    mov cl, buffmaxlen
    mov dx, buff
    int 0x21 /* CF clear on success, AX=number of bytes read */
    jc ERR
    mov blen, al
    jmp CLOSEANDQUIT
 
    ERR:
    mov errv, ax
 
    CLOSEANDQUIT:
    /* close file (if bx contains a handle) */
    cmp bx, 0xffff
    je DONE
    mov ah, 0x3e
    int 0x21
 
    DONE:
    pop dx
    pop cx
    pop bx
    pop ax
  }
 
  /* printf("blen=%u filepos_cx=%u filepos_dx=%u\r\n", blen, filepos_cx, filepos_dx); */
 
  if (errv != 0) nls_outputnl_doserr(errv);
 
  /* on EOF - abort processing the bat file */
  if (blen == 0) goto OOPS;
 
  /* find nearest \n to inc batch offset and replace \r by NULL terminator
   * I support all CR/LF, CR- and LF-terminated batch files */
  for (i = 0; i < blen; i++) {
    if ((buff[i] == '\r') || (buff[i] == '\n')) {
      if ((buff[i] == '\r') && ((i+1) < blen) && (buff[i+1] == '\n')) rmod->bat->nextline += 1;
      break;
    }
  }
  buff[i] = 0;
  rmod->bat->nextline += i + 1;
 
  return(0);
 
  OOPS:
  rmod->bat->fname[0] = 0;
  rmod->bat->nextline = 0;
  return(-1);
}
 
 
/* replaces %-variables in a BAT line with resolved values:
 * %PATH%       -> replaced by the contend of the PATH env variable
 * %UNDEFINED%  -> undefined variables are replaced by nothing ("")
 * %NOTCLOSED   -> NOTCLOSED
 * %1           -> first argument of the batch file (or nothing if no arg) */
static void batpercrepl(char *res, unsigned short ressz, const char *line, const struct rmod_props far *rmod, unsigned short envseg) {
  unsigned short lastperc = 0xffff;
  unsigned short reslen = 0;
 
  if (ressz == 0) return;
  ressz--; /* reserve one byte for the NULL terminator */
 
  for (; (reslen < ressz) && (*line != 0); line++) {
    /* if not a percent, I don't care */
    if (*line != '%') {
      res[reslen++] = *line;
      continue;
    }
 
    /* *** perc char handling *** */
 
    /* closing perc? */
    if (lastperc != 0xffff) {
      /* %% is '%' */
      if (lastperc == reslen) {
        res[reslen++] = '%';
      } else {   /* otherwise variable name */
        const char far *ptr;
        res[reslen] = 0;
        reslen = lastperc;
        ptr = env_lookup_val(envseg, res + reslen);
        if (ptr != NULL) {
          while ((*ptr != 0) && (reslen < ressz)) {
            res[reslen++] = *ptr;
            ptr++;
          }
        }
      }
      lastperc = 0xffff;
      continue;
    }
 
    /* digit? (bat arg) */
    if ((line[1] >= '0') && (line[1] <= '9')) {
      unsigned short argid = line[1] - '0';
      unsigned short i;
      const char far *argv = "";
      if ((rmod != NULL) && (rmod->bat != NULL)) argv = rmod->bat->argv;
 
      /* locate the proper arg */
      for (i = 0; i != argid; i++) {
        /* if string is 0, then end of list reached */
        if (*argv == 0) break;
        /* jump to next arg */
        while (*argv != 0) argv++;
        argv++;
      }
 
      /* copy the arg to result */
      for (i = 0; (argv[i] != 0) && (reslen < ressz); i++) {
        res[reslen++] = argv[i];
      }
      line++;  /* skip the digit */
      continue;
    }
 
    /* opening perc */
    lastperc = reslen;
 
  }
 
  res[reslen] = 0;
}
 
 
 
int main(void) {
  static struct config cfg;
  static unsigned short far *rmod_envseg;
  static unsigned short far *lastexitcode;
  static struct rmod_props far *rmod;
  static char cmdlinebuf[CMDLINE_MAXLEN + 2]; /* 1 extra byte for 0-terminator and another for memguard */
  static char *cmdline;
  static struct redir_data redirprops;
  static enum cmd_result cmdres;
  static unsigned short i; /* general-purpose variable for short-lived things */
  static unsigned char flags;
 
  rmod = rmod_find(BUFFER_len);
  if (rmod == NULL) {
    /* look at command line parameters (in case env size if set there) */
    parse_argv(&cfg);
    rmod = rmod_install(cfg.envsiz, BUFFER, BUFFER_len);
    if (rmod == NULL) {
      outputnl("ERROR: rmod_install() failed");
      return(1);
    }
    /* copy flags to rmod's storage (and enable ECHO) */
    rmod->flags = cfg.flags | FLAG_ECHOFLAG;
    /* printf("rmod installed at %Fp\r\n", rmod); */
    rmod->version = BYTE_VERSION;
  } else {
    /* printf("rmod found at %Fp\r\n", rmod); */
    /* if I was spawned by rmod and FLAG_EXEC_AND_QUIT is set, then I should
     * die asap, because the command has been executed already, so I no longer
     * have a purpose in life */
    if (rmod->flags & FLAG_EXEC_AND_QUIT) sayonara(rmod);
    /* */
    if (rmod->version != BYTE_VERSION) {
      outputnl("SVARCOM VERSION CHANGED. SYSTEM HALTED. PLEASE REBOOT YOUR COMPUTER.");
      _asm {
        HALT:
        hlt
        jmp HALT
      }
    }
  }
 
  /* install a few guardvals in memory to detect some cases of overflows */
  memguard_set(cmdlinebuf);
 
  rmod_envseg = MK_FP(rmod->rmodseg, RMOD_OFFSET_ENVSEG);
  lastexitcode = MK_FP(rmod->rmodseg, RMOD_OFFSET_LEXITCODE);
 
  /* make COMPSEC point to myself */
  set_comspec_to_self(*rmod_envseg);
 
/*  {
    unsigned short envsiz;
    unsigned short far *sizptr = MK_FP(*rmod_envseg - 1, 3);
    envsiz = *sizptr;
    envsiz *= 16;
    printf("rmod_inpbuff at %04X:%04X, env_seg at %04X:0000 (env_size = %u bytes)\r\n", rmod->rmodseg, RMOD_OFFSET_INPBUFF, *rmod_envseg, envsiz);
  }*/
 
  /* on /P check for the presence of AUTOEXEC.BAT and execute it if found,
   * but skip this check if /D was also passed */
  if ((cfg.flags & (FLAG_PERMANENT | FLAG_SKIP_AUTOEXEC)) == FLAG_PERMANENT) {
    if (file_getattr("AUTOEXEC.BAT") >= 0) cfg.execcmd = "AUTOEXEC.BAT";
  }
 
  do {
    /* terminate previous command with a CR/LF if ECHO ON (but not during BAT processing) */
    if ((rmod->flags & FLAG_ECHOFLAG) && (rmod->bat == NULL)) outputnl("");
 
    SKIP_NEWLINE:
 
    /* memory check */
    memguard_check(rmod->rmodseg, cmdlinebuf);
 
    /* preset cmdline to point at the dedicated buffer */
    cmdline = cmdlinebuf;
 
    /* (re)load translation strings if needed */
    nls_langreload(BUFFER, *rmod_envseg);
 
    /* load awaiting command, if any (used to run piped commands) */
    if (rmod->awaitingcmd[0] != 0) {
      _fstrcpy(cmdline, rmod->awaitingcmd);
      rmod->awaitingcmd[0] = 0;
      flags |= DELETE_STDIN_FILE;
      goto EXEC_CMDLINE;
    } else {
      flags &= ~DELETE_STDIN_FILE;
    }
 
    /* skip user input if I have a command to exec (/C or /K) */
    if (cfg.execcmd != NULL) {
      cmdline = cfg.execcmd;
      cfg.execcmd = NULL;
      goto EXEC_CMDLINE;
    }
 
    /* if batch file is being executed -> fetch next line */
    if (rmod->bat != NULL) {
      if (getbatcmd(BUFFER, CMDLINE_MAXLEN, rmod) != 0) { /* end of batch */
        struct batctx far *victim = rmod->bat;
        rmod->bat = rmod->bat->parent;
        rmod_ffree(victim);
        /* end of batch? then restore echo flag as it was before running the (first) bat file */
        if (rmod->bat == NULL) {
          rmod->flags &= ~FLAG_ECHOFLAG;
          if (rmod->flags & FLAG_ECHO_BEFORE_BAT) rmod->flags |= FLAG_ECHOFLAG;
        }
        continue;
      }
      /* %-decoding of variables (%PATH%, %1, %%...), result in cmdline */
      batpercrepl(cmdline, CMDLINE_MAXLEN, BUFFER, rmod, *rmod_envseg);
      /* skip any leading spaces */
      while (*cmdline == ' ') cmdline++;
      /* skip batch labels */
      if (*cmdline == ':') continue;
      /* output prompt and command on screen if echo on and command is not
       * inhibiting it with the @ prefix */
      if ((rmod->flags & FLAG_ECHOFLAG) && (cmdline[0] != '@')) {
        build_and_display_prompt(BUFFER, *rmod_envseg);
        outputnl(cmdline);
      }
      /* skip the @ prefix if present, it is no longer useful */
      if (cmdline[0] == '@') cmdline++;
    } else {
      /* interactive mode: display prompt (if echo enabled) and wait for user
       * command line */
      if (rmod->flags & FLAG_ECHOFLAG) build_and_display_prompt(BUFFER, *rmod_envseg);
      /* collect user input */
      cmdline_getinput(FP_SEG(rmod->inputbuf), FP_OFF(rmod->inputbuf));
      /* copy it to local cmdline */
      if (rmod->inputbuf[1] != 0) _fmemcpy(cmdline, rmod->inputbuf + 2, rmod->inputbuf[1]);
      cmdline[(unsigned)(rmod->inputbuf[1])] = 0; /* zero-terminate local buff (oriignal is '\r'-terminated) */
    }
 
    /* if nothing entered, loop again (but without appending an extra CR/LF) */
    if (cmdline[0] == 0) goto SKIP_NEWLINE;
 
    /* I jump here when I need to exec an initial command (/C or /K) */
    EXEC_CMDLINE:
 
    /* move pointer forward to skip over any leading spaces */
    while (*cmdline == ' ') cmdline++;
 
    /* update rmod's ptr to COMPSPEC so it is always up to date */
    rmod_updatecomspecptr(rmod->rmodseg, *rmod_envseg);
 
    /* handle redirections (if any) */
    i = redir_parsecmd(&redirprops, cmdline, rmod->awaitingcmd, *rmod_envseg);
    if (i != 0) {
      nls_outputnl_doserr(i);
      rmod->awaitingcmd[0] = 0;
      continue;
    }
 
    /* try matching (and executing) an internal command */
    cmdres = cmd_process(rmod, *rmod_envseg, cmdline, BUFFER, sizeof(BUFFER), &redirprops, flags & DELETE_STDIN_FILE);
    if ((cmdres == CMD_OK) || (cmdres == CMD_FAIL)) {
      /* internal command executed */
      continue;
    } else if (cmdres == CMD_CHANGED) { /* cmdline changed, needs to be reprocessed */
      goto EXEC_CMDLINE;
    } else if (cmdres == CMD_CHANGED_BY_CALL) { /* cmdline changed *specifically* by CALL */
      /* the distinction is important since it changes the way batch files are processed */
      flags |= CALL_FLAG;
      goto EXEC_CMDLINE;
    } else if (cmdres == CMD_NOTFOUND) {
      /* this was not an internal command, try matching an external command */
      run_as_external(BUFFER, cmdline, *rmod_envseg, rmod, &redirprops, flags);
      flags &= ~CALL_FLAG; /* reset callflag to make sure it is processed only once */
 
      /* is it a newly launched BAT file? */
      if ((rmod->bat != NULL) && (rmod->bat->nextline == 0)) goto SKIP_NEWLINE;
      /* run_as_external() does not return on success, if I am still alive then
       * external command failed to execute */
      outputnl("Bad command or file name");
      continue;
    }
 
    /* I should never ever land here */
    outputnl("INTERNAL ERR: INVALID CMDRES");
 
    /* repeat unless /C was asked - but always finish running an ongoing batch
     * file (otherwise only first BAT command would be executed with /C) */
  } while (((rmod->flags & FLAG_EXEC_AND_QUIT) == 0) || (rmod->bat != NULL));
 
  sayonara(rmod);
  return(0);
}
 

Rev 960	Rev 963
1	`/* This file is part of the SvarCOM project and is published under the terms`	1	`/* This file is part of the SvarCOM project and is published under the terms`
2	`* of the MIT license.`	2	`* of the MIT license.`
3	`*`	3	`*`
4	`* Copyright (C) 2021-2022 Mateusz Viste`	4	`* Copyright (C) 2021-2022 Mateusz Viste`
5	`*`	5	`*`
6	`* Permission is hereby granted, free of charge, to any person obtaining a`	6	`* Permission is hereby granted, free of charge, to any person obtaining a`
7	`* copy of this software and associated documentation files (the "Software"),`	7	`* copy of this software and associated documentation files (the "Software"),`
8	`* to deal in the Software without restriction, including without limitation`	8	`* to deal in the Software without restriction, including without limitation`
9	`* the rights to use, copy, modify, merge, publish, distribute, sublicense,`	9	`* the rights to use, copy, modify, merge, publish, distribute, sublicense,`
10	`* and/or sell copies of the Software, and to permit persons to whom the`	10	`* and/or sell copies of the Software, and to permit persons to whom the`
11	`* Software is furnished to do so, subject to the following conditions:`	11	`* Software is furnished to do so, subject to the following conditions:`
12	`*`	12	`*`
13	`* The above copyright notice and this permission notice shall be included in`	13	`* The above copyright notice and this permission notice shall be included in`
14	`* all copies or substantial portions of the Software.`	14	`* all copies or substantial portions of the Software.`
15	`*`	15	`*`
16	`* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR`	16	`* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR`
17	`* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,`	17	`* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,`
18	`* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE`	18	`* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE`
19	`* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER`	19	`* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER`
20	`* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING`	20	`* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING`
21	`* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER`	21	`* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER`
22	`* DEALINGS IN THE SOFTWARE.`	22	`* DEALINGS IN THE SOFTWARE.`
23	`*/`	23	`*/`
24		24
25	`#include <i86.h>`	25	`#include <i86.h>`
26	`#include <dos.h>`	26	`#include <dos.h>`
27	`#include <stdio.h>`	27	`#include <stdio.h>`
28	`#include <stdlib.h>`	28	`#include <stdlib.h>`
29	`#include <string.h>`	29	`#include <string.h>`
30		30
31	`#include <process.h>`	31	`#include <process.h>`
32		32
33	`#include "cmd.h"`	33	`#include "cmd.h"`
34	`#include "env.h"`	34	`#include "env.h"`
35	`#include "helpers.h"`	35	`#include "helpers.h"`
36	`#include "redir.h"`	36	`#include "redir.h"`
37	`#include "rmodinit.h"`	37	`#include "rmodinit.h"`
38	`#include "sayonara.h"`	38	`#include "sayonara.h"`
39		39
40	`#include "rmodcore.h" /* rmod binary inside a BUFFER array */`	40	`#include "rmodcore.h" /* rmod binary inside a BUFFER array */`
41		41
42	`/* this version byte is used to tag RMOD so I can easily make sure that`	42	`/* this version byte is used to tag RMOD so I can easily make sure that`
43	`* the RMOD struct I find in memory is one that I know. Should the version`	43	`* the RMOD struct I find in memory is one that I know. Should the version`
44	`* mismatch, then it would likely mean that SvarCOM has been upgraded and`	44	`* mismatch, then it would likely mean that SvarCOM has been upgraded and`
45	`* RMOD should not be accessed as its structure might no longer be in sync`	45	`* RMOD should not be accessed as its structure might no longer be in sync`
46	`* with what I think it is.`	46	`* with what I think it is.`
47	`* * INCREMENT THIS AT EACH NEW SVARCOM RELEASE! * */`	47	`* * INCREMENT THIS AT EACH NEW SVARCOM RELEASE! * */`
48	`#define BYTE_VERSION 3`	48	`#define BYTE_VERSION 3`
49		49
50		50
51	`struct config {`	51	`struct config {`
52	`unsigned char flags; /* command.com flags, as defined in rmodinit.h */`	52	`unsigned char flags; /* command.com flags, as defined in rmodinit.h */`
53	`char *execcmd;`	53	`char *execcmd;`
54	`unsigned short envsiz;`	54	`unsigned short envsiz;`
55	`};`	55	`};`
56		56
57	`/* max length of the cmdline storage (bytes) - includes also max length of`	57	`/* max length of the cmdline storage (bytes) - includes also max length of`
58	`* line loaded from a BAT file (no more than 255 bytes!) */`	58	`* line loaded from a BAT file (no more than 255 bytes!) */`
59	`#define CMDLINE_MAXLEN 255`	59	`#define CMDLINE_MAXLEN 255`
60		60
61		61
62	`/* sets guard values at a few places in memory for later detection of`	62	`/* sets guard values at a few places in memory for later detection of`
63	`* overflows via memguard_check() */`	63	`* overflows via memguard_check() */`
64	`static void memguard_set(char *cmdlinebuf) {`	64	`static void memguard_set(char *cmdlinebuf) {`
65	`BUFFER[sizeof(BUFFER) - 1] = 0xC7;`	65	`BUFFER[sizeof(BUFFER) - 1] = 0xC7;`
66	`cmdlinebuf[CMDLINE_MAXLEN] = 0xC7;`	66	`cmdlinebuf[CMDLINE_MAXLEN] = 0xC7;`
67	`}`	67	`}`
68		68
69		69
70	`/* checks for valguards at specific memory locations, returns 0 on success */`	70	`/* checks for valguards at specific memory locations, returns 0 on success */`
71	`static int memguard_check(unsigned short rmodseg, char *cmdlinebuf) {`	71	`static int memguard_check(unsigned short rmodseg, char *cmdlinebuf) {`
72	`/* check RMOD signature (would be overwritten in case of stack overflow */`	72	`/* check RMOD signature (would be overwritten in case of stack overflow */`
73	`static char msg[] = "!! MEMORY CORRUPTION ## DETECTED !!";`	73	`static char msg[] = "!! MEMORY CORRUPTION ## DETECTED !!";`
74	`unsigned short far *rmodsig = MK_FP(rmodseg, 0x100 + 6);`	74	`unsigned short far *rmodsig = MK_FP(rmodseg, 0x100 + 6);`
75	`unsigned char far *rmod = MK_FP(rmodseg, 0);`	75	`unsigned char far *rmod = MK_FP(rmodseg, 0);`
76		76
77	`if (*rmodsig != 0x2019) {`	77	`if (*rmodsig != 0x2019) {`
78	`msg[22] = '1';`	78	`msg[22] = '1';`
79	`goto FAIL;`	79	`goto FAIL;`
80	`}`	80	`}`
81		81
82	`/* check last BUFFER byte */`	82	`/* check last BUFFER byte */`
83	`if (BUFFER[sizeof(BUFFER) - 1] != 0xC7) {`	83	`if (BUFFER[sizeof(BUFFER) - 1] != 0xC7) {`
84	`msg[22] = '2';`	84	`msg[22] = '2';`
85	`goto FAIL;`	85	`goto FAIL;`
86	`}`	86	`}`
87		87
88	`/* check last cmdlinebuf byte */`	88	`/* check last cmdlinebuf byte */`
89	`if (cmdlinebuf[CMDLINE_MAXLEN] != 0xC7) {`	89	`if (cmdlinebuf[CMDLINE_MAXLEN] != 0xC7) {`
90	`msg[22] = '3';`	90	`msg[22] = '3';`
91	`goto FAIL;`	91	`goto FAIL;`
92	`}`	92	`}`
93		93
94	`/* check rmod exec buf */`	94	`/* check rmod exec buf */`
95	`if (rmod[RMOD_OFFSET_EXECPROG + 127] != 0) {`	95	`if (rmod[RMOD_OFFSET_EXECPROG + 127] != 0) {`
96	`msg[22] = '4';`	96	`msg[22] = '4';`
97	`goto FAIL;`	97	`goto FAIL;`
98	`}`	98	`}`
99		99
100	`/* check rmod exec stdin buf */`	100	`/* check rmod exec stdin buf */`
101	`if (rmod[RMOD_OFFSET_STDINFILE + 127] != 0) {`	101	`if (rmod[RMOD_OFFSET_STDINFILE + 127] != 0) {`
102	`msg[22] = '5';`	102	`msg[22] = '5';`
103	`goto FAIL;`	103	`goto FAIL;`
104	`}`	104	`}`
105		105
106	`/* check rmod exec stdout buf */`	106	`/* check rmod exec stdout buf */`
107	`if (rmod[RMOD_OFFSET_STDOUTFILE + 127] != 0) {`	107	`if (rmod[RMOD_OFFSET_STDOUTFILE + 127] != 0) {`
108	`msg[22] = '6';`	108	`msg[22] = '6';`
109	`goto FAIL;`	109	`goto FAIL;`
110	`}`	110	`}`
111		111
112	`/* else all good */`	112	`/* else all good */`
113	`return(0);`	113	`return(0);`
114		114
115	`/* error handling */`	115	`/* error handling */`
116	`FAIL:`	116	`FAIL:`
117	`outputnl(msg);`	117	`outputnl(msg);`
118	`return(1);`	118	`return(1);`
119	`}`	119	`}`
120		120
121		121
122	`/* parses command line the hard way (directly from PSP) */`	122	`/* parses command line the hard way (directly from PSP) */`
123	`static void parse_argv(struct config *cfg) {`	123	`static void parse_argv(struct config *cfg) {`
124	`const unsigned char cmdlinelen = (void )0x80;`	124	`const unsigned char cmdlinelen = (void )0x80;`
125	`char cmdline = (void )0x81;`	125	`char cmdline = (void )0x81;`
126		126
127	`memset(cfg, 0, sizeof(*cfg));`	127	`memset(cfg, 0, sizeof(*cfg));`
128		128
129	`/* set a NULL terminator on cmdline */`	129	`/* set a NULL terminator on cmdline */`
130	`cmdline[*cmdlinelen] = 0;`	130	`cmdline[*cmdlinelen] = 0;`
131		131
132	`while (*cmdline != 0) {`	132	`while (*cmdline != 0) {`
133		133
134	`/* skip over any leading spaces */`	134	`/* skip over any leading spaces */`
135	`if (*cmdline == ' ') {`	135	`if (*cmdline == ' ') {`
136	`cmdline++;`	136	`cmdline++;`
137	`continue;`	137	`continue;`
138	`}`	138	`}`
139		139
140	`if (*cmdline != '/') {`	140	`if (*cmdline != '/') {`
141	`output("Invalid parameter: ");`	141	`output("Invalid parameter: ");`
142	`outputnl(cmdline);`	142	`outputnl(cmdline);`
143	`goto SKIP_TO_NEXT_ARG;`	143	`goto SKIP_TO_NEXT_ARG;`
144	`}`	144	`}`
145		145
146	`/* got a slash */`	146	`/* got a slash */`
147	`cmdline++; /* skip the slash */`	147	`cmdline++; /* skip the slash */`
148	`switch (*cmdline) {`	148	`switch (*cmdline) {`
149	`case 'c': /* /C = execute command and quit */`	149	`case 'c': /* /C = execute command and quit */`
150	`case 'C':`	150	`case 'C':`
151	`cfg->flags \|= FLAG_EXEC_AND_QUIT;`	151	`cfg->flags \|= FLAG_EXEC_AND_QUIT;`
152	`/* FALLTHRU */`	152	`/* FALLTHRU */`
153	`case 'k': /* /K = execute command and keep running */`	153	`case 'k': /* /K = execute command and keep running */`
154	`case 'K':`	154	`case 'K':`
155	`cfg->execcmd = cmdline + 1;`	155	`cfg->execcmd = cmdline + 1;`
156	`return;`	156	`return;`
157		157
158	`case 'd': /* /D = skip autoexec.bat processing */`	158	`case 'd': /* /D = skip autoexec.bat processing */`
159	`case 'D':`	159	`case 'D':`
160	`cfg->flags \|= FLAG_SKIP_AUTOEXEC;`	160	`cfg->flags \|= FLAG_SKIP_AUTOEXEC;`
161	`break;`	161	`break;`
162		162
163	`case 'e': /* preset the initial size of the environment block */`	163	`case 'e': /* preset the initial size of the environment block */`
164	`case 'E':`	164	`case 'E':`
165	`cmdline++;`	165	`cmdline++;`
166	`if (cmdline == ':') cmdline++; / could be /E:size */`	166	`if (cmdline == ':') cmdline++; / could be /E:size */`
167	`atous(&(cfg->envsiz), cmdline);`	167	`atous(&(cfg->envsiz), cmdline);`
168	`if (cfg->envsiz < 64) cfg->envsiz = 0;`	168	`if (cfg->envsiz < 64) cfg->envsiz = 0;`
169	`break;`	169	`break;`
170		170
171	`case 'p': /* permanent shell (can't exit + run autoexec.bat) */`	171	`case 'p': /* permanent shell (can't exit + run autoexec.bat) */`
172	`case 'P':`	172	`case 'P':`
173	`cfg->flags \|= FLAG_PERMANENT;`	173	`cfg->flags \|= FLAG_PERMANENT;`
174	`break;`	174	`break;`
175		175
176	`case '?':`	176	`case '?':`
177	`outputnl("Starts the SvarCOM command interpreter");`	177	`outputnl("Starts the SvarCOM command interpreter");`
178	`outputnl("");`	178	`outputnl("");`
179	`outputnl("COMMAND /E:nnn [/[C\|K] [/P] [/D] command]");`	179	`outputnl("COMMAND /E:nnn [/[C\|K] [/P] [/D] command]");`
180	`outputnl("");`	180	`outputnl("");`
181	`outputnl("/D Skip AUTOEXEC.BAT processing (makes sense only with /P)");`	181	`outputnl("/D Skip AUTOEXEC.BAT processing (makes sense only with /P)");`
182	`outputnl("/E:nnn Sets the environment size to nnn bytes");`	182	`outputnl("/E:nnn Sets the environment size to nnn bytes");`
183	`outputnl("/P Makes the new command interpreter permanent and run AUTOEXEC.BAT");`	183	`outputnl("/P Makes the new command interpreter permanent and run AUTOEXEC.BAT");`
184	`outputnl("/C Executes the specified command and returns");`	184	`outputnl("/C Executes the specified command and returns");`
185	`outputnl("/K Executes the specified command and continues running");`	185	`outputnl("/K Executes the specified command and continues running");`
186	`exit(1);`	186	`exit(1);`
187	`break;`	187	`break;`
188		188
189	`default:`	189	`default:`
190	`output("Invalid switch: /");`	190	`output("Invalid switch: /");`
191	`outputnl(cmdline);`	191	`outputnl(cmdline);`
192	`break;`	192	`break;`
193	`}`	193	`}`
194		194
195	`/* move to next argument or quit processing if end of cmdline */`	195	`/* move to next argument or quit processing if end of cmdline */`
196	`SKIP_TO_NEXT_ARG:`	196	`SKIP_TO_NEXT_ARG:`
197	`while ((cmdline != 0) && (cmdline != ' ') && (*cmdline != '/')) cmdline++;`	197	`while ((cmdline != 0) && (cmdline != ' ') && (*cmdline != '/')) cmdline++;`
198	`}`	198	`}`
199	`}`	199	`}`
200		200
201		201
202	`/* builds the prompt string and displays it. buff is filled with a zero-terminated copy of the prompt. */`	202	`/* builds the prompt string and displays it. buff is filled with a zero-terminated copy of the prompt. */`
203	`static void build_and_display_prompt(char *buff, unsigned short envseg) {`	203	`static void build_and_display_prompt(char *buff, unsigned short envseg) {`
204	`char *s = buff;`	204	`char *s = buff;`
205	`/* locate the prompt variable or use the default pattern */`	205	`/* locate the prompt variable or use the default pattern */`
206	`const char far *fmt = env_lookup_val(envseg, "PROMPT");`	206	`const char far *fmt = env_lookup_val(envseg, "PROMPT");`
207	`if ((fmt == NULL) \|\| (fmt == 0)) fmt = "$p$g"; / fallback to default if empty */`	207	`if ((fmt == NULL) \|\| (fmt == 0)) fmt = "$p$g"; / fallback to default if empty */`
208	`/* build the prompt string based on pattern */`	208	`/* build the prompt string based on pattern */`
209	`for (; *fmt != 0; fmt++) {`	209	`for (; *fmt != 0; fmt++) {`
210	`if (*fmt != '$') {`	210	`if (*fmt != '$') {`
211	`s = fmt;`	211	`s = fmt;`
212	`s++;`	212	`s++;`
213	`continue;`	213	`continue;`
214	`}`	214	`}`
215	`/* escape code ($P, etc) */`	215	`/* escape code ($P, etc) */`
216	`fmt++;`	216	`fmt++;`
217	`switch (*fmt) {`	217	`switch (*fmt) {`
218	`case 'Q': /* $Q = = (equal sign) */`	218	`case 'Q': /* $Q = = (equal sign) */`
219	`case 'q':`	219	`case 'q':`
220	`*s = '=';`	220	`*s = '=';`
221	`s++;`	221	`s++;`
222	`break;`	222	`break;`
223	`case '$': /* $$ = $ (dollar sign) */`	223	`case '$': /* $$ = $ (dollar sign) */`
224	`*s = '$';`	224	`*s = '$';`
225	`s++;`	225	`s++;`
226	`break;`	226	`break;`
227	`case 'T': /* $t = current time */`	227	`case 'T': /* $t = current time */`
228	`case 't':`	228	`case 't':`
229	`s += sprintf(s, "00:00"); /* TODO */`	229	`s += sprintf(s, "00:00"); /* TODO */`
230	`break;`	230	`break;`
231	`case 'D': /* $D = current date */`	231	`case 'D': /* $D = current date */`
232	`case 'd':`	232	`case 'd':`
233	`s += sprintf(s, "1985-07-29"); /* TODO */`	233	`s += sprintf(s, "1985-07-29"); /* TODO */`
234	`break;`	234	`break;`
235	`case 'P': /* $P = current drive and path */`	235	`case 'P': /* $P = current drive and path */`
236	`case 'p':`	236	`case 'p':`
237	`_asm {`	237	`_asm {`
238	`mov ah, 0x19 /* DOS 1+ - GET CURRENT DRIVE */`	238	`mov ah, 0x19 /* DOS 1+ - GET CURRENT DRIVE */`
239	`int 0x21`	239	`int 0x21`
240	`mov bx, s`	240	`mov bx, s`
241	`mov [bx], al /* AL = drive (00 = A:, 01 = B:, etc */`	241	`mov [bx], al /* AL = drive (00 = A:, 01 = B:, etc */`
242	`}`	242	`}`
243	`*s += 'A';`	243	`*s += 'A';`
244	`s++;`	244	`s++;`
245	`*s = ':';`	245	`*s = ':';`
246	`s++;`	246	`s++;`
247	`*s = '\\';`	247	`*s = '\\';`
248	`s++;`	248	`s++;`
249	`_asm {`	249	`_asm {`
250	`mov ah, 0x47 /* DOS 2+ - CWD - GET CURRENT DIRECTORY */`	250	`mov ah, 0x47 /* DOS 2+ - CWD - GET CURRENT DIRECTORY */`
251	`xor dl,dl /* DL = drive number (00h = default, 01h = A:, etc) */`	251	`xor dl,dl /* DL = drive number (00h = default, 01h = A:, etc) */`
252	`mov si, s /* DS:SI -> 64-byte buffer for ASCIZ pathname */`	252	`mov si, s /* DS:SI -> 64-byte buffer for ASCIZ pathname */`
253	`int 0x21`	253	`int 0x21`
254	`jc DONE /* leave path empty on error */`	254	`jc DONE /* leave path empty on error */`
255	`/* move s ptr forward to end (0-termintor) of pathname */`	255	`/* move s ptr forward to end (0-termintor) of pathname */`
256	`NEXTBYTE:`	256	`NEXTBYTE:`
257	`mov si, s`	257	`mov si, s`
258	`cmp byte ptr [si], 0`	258	`cmp byte ptr [si], 0`
259	`je DONE`	259	`je DONE`
260	`inc s`	260	`inc s`
261	`jmp NEXTBYTE`	261	`jmp NEXTBYTE`
262	`DONE:`	262	`DONE:`
263	`}`	263	`}`
264	`break;`	264	`break;`
265	`case 'V': /* $V = DOS version number */`	265	`case 'V': /* $V = DOS version number */`
266	`case 'v':`	266	`case 'v':`
267	`s += sprintf(s, "VER"); /* TODO */`	267	`s += sprintf(s, "VER"); /* TODO */`
268	`break;`	268	`break;`
269	`case 'N': /* $N = current drive */`	269	`case 'N': /* $N = current drive */`
270	`case 'n':`	270	`case 'n':`
271	`_asm {`	271	`_asm {`
272	`mov ah, 0x19 /* DOS 1+ - GET CURRENT DRIVE */`	272	`mov ah, 0x19 /* DOS 1+ - GET CURRENT DRIVE */`
273	`int 0x21`	273	`int 0x21`
274	`mov bx, s`	274	`mov bx, s`
275	`mov [bx], al /* AL = drive (00 = A:, 01 = B:, etc */`	275	`mov [bx], al /* AL = drive (00 = A:, 01 = B:, etc */`
276	`}`	276	`}`
277	`*s += 'A';`	277	`*s += 'A';`
278	`s++;`	278	`s++;`
279	`break;`	279	`break;`
280	`case 'G': /* $G = > (greater-than sign) */`	280	`case 'G': /* $G = > (greater-than sign) */`
281	`case 'g':`	281	`case 'g':`
282	`*s = '>';`	282	`*s = '>';`
283	`s++;`	283	`s++;`
284	`break;`	284	`break;`
285	`case 'L': /* $L = < (less-than sign) */`	285	`case 'L': /* $L = < (less-than sign) */`
286	`case 'l':`	286	`case 'l':`
287	`*s = '<';`	287	`*s = '<';`
288	`s++;`	288	`s++;`
289	`break;`	289	`break;`
290	`case 'B': /* $B = \| (pipe) */`	290	`case 'B': /* $B = \| (pipe) */`
291	`case 'b':`	291	`case 'b':`
292	`*s = '\|';`	292	`*s = '\|';`
293	`s++;`	293	`s++;`
294	`break;`	294	`break;`
295	`case 'H': /* $H = backspace (erases previous character) */`	295	`case 'H': /* $H = backspace (erases previous character) */`
296	`case 'h':`	296	`case 'h':`
297	`*s = '\b';`	297	`*s = '\b';`
298	`s++;`	298	`s++;`
299	`break;`	299	`break;`
300	`case 'E': /* $E = Escape code (ASCII 27) */`	300	`case 'E': /* $E = Escape code (ASCII 27) */`
301	`case 'e':`	301	`case 'e':`
302	`*s = 27;`	302	`*s = 27;`
303	`s++;`	303	`s++;`
304	`break;`	304	`break;`
305	`case '_': /* $_ = CR+LF */`	305	`case '_': /* $_ = CR+LF */`
306	`*s = '\r';`	306	`*s = '\r';`
307	`s++;`	307	`s++;`
308	`*s = '\n';`	308	`*s = '\n';`
309	`s++;`	309	`s++;`
310	`break;`	310	`break;`
311	`}`	311	`}`
312	`}`	312	`}`
313	`*s = 0;`	313	`*s = 0;`
314	`output(buff);`	314	`output(buff);`
315	`}`	315	`}`
316		316
317		317
318	`/* a few internal flags */`	318	`/* a few internal flags */`
319	`#define DELETE_STDIN_FILE 1`	319	`#define DELETE_STDIN_FILE 1`
320	`#define CALL_FLAG 2`	320	`#define CALL_FLAG 2`
321		321
322	`static void run_as_external(char buff, const char cmdline, unsigned short envseg, struct rmod_props far rmod, struct redir_data redir, unsigned char flags) {`	322	`static void run_as_external(char buff, const char cmdline, unsigned short envseg, struct rmod_props far rmod, struct redir_data redir, unsigned char flags) {`
323	`char *cmdfile = buff + 512;`	323	`char *cmdfile = buff + 512;`
324	`const char far *pathptr;`	324	`const char far *pathptr;`
325	`int lookup;`	325	`int lookup;`
326	`unsigned short i;`	326	`unsigned short i;`
327	`const char *ext;`	327	`const char *ext;`
328	`char *cmd = buff + 1024;`	328	`char *cmd = buff + 1024;`
329	`const char *cmdtail;`	329	`const char *cmdtail;`
330	`char far *rmod_execprog = MK_FP(rmod->rmodseg, RMOD_OFFSET_EXECPROG);`	330	`char far *rmod_execprog = MK_FP(rmod->rmodseg, RMOD_OFFSET_EXECPROG);`
331	`char far *rmod_cmdtail = MK_FP(rmod->rmodseg, 0x81);`	331	`char far *rmod_cmdtail = MK_FP(rmod->rmodseg, 0x81);`
332	`_Packed struct {`	332	`_Packed struct {`
333	`unsigned short envseg;`	333	`unsigned short envseg;`
334	`unsigned long cmdtail;`	334	`unsigned long cmdtail;`
335	`unsigned long fcb1;`	335	`unsigned long fcb1;`
336	`unsigned long fcb2;`	336	`unsigned long fcb2;`
337	`} far *ExecParam = MK_FP(rmod->rmodseg, RMOD_OFFSET_EXECPARAM);`	337	`} far *ExecParam = MK_FP(rmod->rmodseg, RMOD_OFFSET_EXECPARAM);`
338		338
339	`/* find cmd and cmdtail */`	339	`/* find cmd and cmdtail */`
340	`i = 0;`	340	`i = 0;`
341	`cmdtail = cmdline;`	341	`cmdtail = cmdline;`
342	`while (cmdtail == ' ') cmdtail++; / skip any leading spaces */`	342	`while (cmdtail == ' ') cmdtail++; / skip any leading spaces */`
343	`while ((cmdtail != ' ') && (cmdtail != '/') && (cmdtail != '+') && (cmdtail != 0)) {`	343	`while ((cmdtail != ' ') && (cmdtail != '/') && (cmdtail != '+') && (cmdtail != 0)) {`
344	`cmd[i++] = *cmdtail;`	344	`cmd[i++] = *cmdtail;`
345	`cmdtail++;`	345	`cmdtail++;`
346	`}`	346	`}`
347	`cmd[i] = 0;`	347	`cmd[i] = 0;`
348		348
349	`/* is this a command in curdir? */`	349	`/* is this a command in curdir? */`
350	`lookup = lookup_cmd(cmdfile, cmd, NULL, &ext);`	350	`lookup = lookup_cmd(cmdfile, cmd, NULL, &ext);`
351	`if (lookup == 0) {`	351	`if (lookup == 0) {`
352	`/* printf("FOUND LOCAL EXEC FILE: '%s'\r\n", cmdfile); */`	352	`/* printf("FOUND LOCAL EXEC FILE: '%s'\r\n", cmdfile); */`
353	`goto RUNCMDFILE;`	353	`goto RUNCMDFILE;`
354	`} else if (lookup == -2) {`	354	`} else if (lookup == -2) {`
355	`/* puts("NOT FOUND"); */`	355	`/* puts("NOT FOUND"); */`
356	`return;`	356	`return;`
357	`}`	357	`}`
358		358
359	`/* try matching something in PATH */`	359	`/* try matching something in PATH */`
360	`pathptr = env_lookup_val(envseg, "PATH");`	360	`pathptr = env_lookup_val(envseg, "PATH");`
361		361
362	`/* try each path in %PATH% */`	362	`/* try each path in %PATH% */`
363	`while (pathptr) {`	363	`while (pathptr) {`
364	`for (i = 0;; i++) {`	364	`for (i = 0;; i++) {`
365	`buff[i] = *pathptr;`	365	`buff[i] = *pathptr;`
366	`if ((buff[i] == 0) \|\| (buff[i] == ';')) break;`	366	`if ((buff[i] == 0) \|\| (buff[i] == ';')) break;`
367	`pathptr++;`	367	`pathptr++;`
368	`}`	368	`}`
369	`buff[i] = 0;`	369	`buff[i] = 0;`
370	`lookup = lookup_cmd(cmdfile, cmd, buff, &ext);`	370	`lookup = lookup_cmd(cmdfile, cmd, buff, &ext);`
371	`if (lookup == 0) goto RUNCMDFILE;`	371	`if (lookup == 0) goto RUNCMDFILE;`
372	`if (lookup == -2) return;`	372	`if (lookup == -2) return;`
373	`if (*pathptr == ';') {`	373	`if (*pathptr == ';') {`
374	`pathptr++;`	374	`pathptr++;`
375	`} else {`	375	`} else {`
376	`break;`	376	`break;`
377	`}`	377	`}`
378	`}`	378	`}`
379		379
380	`/* last chance: is it an executable link? (trim extension from cmd first) */`	380	`/* last chance: is it an executable link? (trim extension from cmd first) */`
381	`for (i = 0; (cmd[i] != 0) && (cmd[i] != '.') && (i < 9); i++) buff[128 + i] = cmd[i];`	381	`for (i = 0; (cmd[i] != 0) && (cmd[i] != '.') && (i < 9); i++) buff[128 + i] = cmd[i];`
382	`buff[128 + i] = 0;`	382	`buff[128 + i] = 0;`
383	`if ((i < 9) && (link_computefname(buff, buff + 128, envseg) == 0)) {`	383	`if ((i < 9) && (link_computefname(buff, buff + 128, envseg) == 0)) {`
384	`/* try opening the link file (if it exists) and read it into buff */`	384	`/* try opening the link file (if it exists) and read it into buff */`
385	`i = 0;`	385	`i = 0;`
386	`_asm {`	386	`_asm {`
387	`push ax`	387	`push ax`
388	`push bx`	388	`push bx`
389	`push cx`	389	`push cx`
390	`push dx`	390	`push dx`
391		391
392	`mov ax, 0x3d00 /* DOS 2+ - OPEN EXISTING FILE, READ-ONLY */`	392	`mov ax, 0x3d00 /* DOS 2+ - OPEN EXISTING FILE, READ-ONLY */`
393	`mov dx, buff /* file name */`	393	`mov dx, buff /* file name */`
394	`int 0x21`	394	`int 0x21`
395	`jc ERR_FOPEN`	395	`jc ERR_FOPEN`
396	`/* file handle in AX, read from file now */`	396	`/* file handle in AX, read from file now */`
397	`mov bx, ax /* file handle */`	397	`mov bx, ax /* file handle */`
398	`mov ah, 0x3f /* Read from file via handle bx */`	398	`mov ah, 0x3f /* Read from file via handle bx */`
399	`mov cx, 128 /* up to 128 bytes */`	399	`mov cx, 128 /* up to 128 bytes */`
400	`/* mov dx, buff / / dest buffer (already set) */`	400	`/* mov dx, buff / / dest buffer (already set) */`
401	`int 0x21 /* read up to 256 bytes from file and write to buff */`	401	`int 0x21 /* read up to 256 bytes from file and write to buff */`
402	`jc ERR_READ`	402	`jc ERR_READ`
403	`mov i, ax`	403	`mov i, ax`
404	`ERR_READ:`	404	`ERR_READ:`
405	`mov ah, 0x3e /* close file handle in BX */`	405	`mov ah, 0x3e /* close file handle in BX */`
406	`int 0x21`	406	`int 0x21`
407	`ERR_FOPEN:`	407	`ERR_FOPEN:`
408		408
409	`pop dx`	409	`pop dx`
410	`pop cx`	410	`pop cx`
411	`pop bx`	411	`pop bx`
412	`pop ax`	412	`pop ax`
413	`}`	413	`}`
414		414
415	`/* did I read anything? */`	415	`/* did I read anything? */`
416	`if (i != 0) {`	416	`if (i != 0) {`
417	`buff[i] = 0;`	417	`buff[i] = 0;`
418	`/* trim buff at first \n or \r, just in case someone fiddled with the`	418	`/* trim buff at first \n or \r, just in case someone fiddled with the`
419	`* link file using a text editor */`	419	`* link file using a text editor */`
420	`for (i = 0; (buff[i] != 0) && (buff[i] != '\r') && (buff[i] != '\n'); i++);`	420	`for (i = 0; (buff[i] != 0) && (buff[i] != '\r') && (buff[i] != '\n'); i++);`
421	`buff[i] = 0;`	421	`buff[i] = 0;`
422	`/* lookup check */`	422	`/* lookup check */`
423	`if (buff[0] != 0) {`	423	`if (buff[0] != 0) {`
424	`lookup = lookup_cmd(cmdfile, cmd, buff, &ext);`	424	`lookup = lookup_cmd(cmdfile, cmd, buff, &ext);`
425	`if (lookup == 0) goto RUNCMDFILE;`	425	`if (lookup == 0) goto RUNCMDFILE;`
426	`}`	426	`}`
427	`}`	427	`}`
428	`}`	428	`}`
429		429
430	`/* all failed (ie. executable file not found) */`	430	`/* all failed (ie. executable file not found) */`
431	`return;`	431	`return;`
432		432
433	`RUNCMDFILE:`	433	`RUNCMDFILE:`
434		434
435	`/* special handling of batch files */`	435	`/* special handling of batch files */`
436	`if ((ext != NULL) && (imatch(ext, "bat"))) {`	436	`if ((ext != NULL) && (imatch(ext, "bat"))) {`
437	`struct batctx far *newbat;`	437	`struct batctx far *newbat;`
438		438
439	`/* remember the echo flag (in case bat file disables echo, only when starting first bat) */`	439	`/* remember the echo flag (in case bat file disables echo, only when starting first bat) */`
440	`if (rmod->bat == NULL) {`	440	`if (rmod->bat == NULL) {`
441	`rmod->flags &= ~FLAG_ECHO_BEFORE_BAT;`	441	`rmod->flags &= ~FLAG_ECHO_BEFORE_BAT;`
442	`if (rmod->flags & FLAG_ECHOFLAG) rmod->flags \|= FLAG_ECHO_BEFORE_BAT;`	442	`if (rmod->flags & FLAG_ECHOFLAG) rmod->flags \|= FLAG_ECHO_BEFORE_BAT;`
443	`}`	443	`}`
444		444
445	`/* if bat is not called via a CALL, then free the bat-context linked list */`	445	`/* if bat is not called via a CALL, then free the bat-context linked list */`
446	`if ((flags & CALL_FLAG) == 0) {`	446	`if ((flags & CALL_FLAG) == 0) rmod_free_bat_llist(rmod);`
447	`while (rmod->bat != NULL) {`	-
448	`struct batctx far *victim = rmod->bat;`	-
449	`rmod->bat = rmod->bat->parent;`	-
450	`rmod_ffree(victim);`	-
451	`}`	-
452	`}`	447
453	`/* allocate a new bat context */`	448	`/* allocate a new bat context */`
454	`newbat = rmod_fcalloc(sizeof(struct batctx), rmod->rmodseg, "SVBATCTX");`	449	`newbat = rmod_fcalloc(sizeof(struct batctx), rmod->rmodseg, "SVBATCTX");`
455	`if (newbat == NULL) {`	450	`if (newbat == NULL) {`
456	`nls_outputnl_doserr(8); /* insufficient memory */`	451	`nls_outputnl_doserr(8); /* insufficient memory */`
457	`return;`	452	`return;`
458	`}`	453	`}`
459		454
460	`/* fill the newly allocated batctx structure */`	455	`/* fill the newly allocated batctx structure */`
461	`_fstrcpy(newbat->fname, cmdfile); /* truename of the BAT file */`	456	`_fstrcpy(newbat->fname, cmdfile); /* truename of the BAT file */`
462	`/* explode args of the bat file and store them in rmod buff */`	457	`/* explode args of the bat file and store them in rmod buff */`
463	`cmd_explode(buff, cmdline, NULL);`	458	`cmd_explode(buff, cmdline, NULL);`
464	`_fmemcpy(newbat->argv, buff, sizeof(newbat->argv));`	459	`_fmemcpy(newbat->argv, buff, sizeof(newbat->argv));`
465		460
466	`/* push the new bat to the top of rmod's linked list */`	461	`/* push the new bat to the top of rmod's linked list */`
467	`newbat->parent = rmod->bat;`	462	`newbat->parent = rmod->bat;`
468	`rmod->bat = newbat;`	463	`rmod->bat = newbat;`
469		464
470	`return;`	465	`return;`
471	`}`	466	`}`
472		467
473	`/* copy full filename to execute, along with redirected files (if any) */`	468	`/* copy full filename to execute, along with redirected files (if any) */`
474	`_fstrcpy(rmod_execprog, cmdfile);`	469	`_fstrcpy(rmod_execprog, cmdfile);`
475		470
476	`/* copy stdin file if a redirection is needed */`	471	`/* copy stdin file if a redirection is needed */`
477	`if (redir->stdinfile) {`	472	`if (redir->stdinfile) {`
478	`char far *farptr = MK_FP(rmod->rmodseg, RMOD_OFFSET_STDINFILE);`	473	`char far *farptr = MK_FP(rmod->rmodseg, RMOD_OFFSET_STDINFILE);`
479	`char far *delstdin = MK_FP(rmod->rmodseg, RMOD_OFFSET_STDIN_DEL);`	474	`char far *delstdin = MK_FP(rmod->rmodseg, RMOD_OFFSET_STDIN_DEL);`
480	`_fstrcpy(farptr, redir->stdinfile);`	475	`_fstrcpy(farptr, redir->stdinfile);`
481	`if (flags & DELETE_STDIN_FILE) {`	476	`if (flags & DELETE_STDIN_FILE) {`
482	`*delstdin = redir->stdinfile[0];`	477	`*delstdin = redir->stdinfile[0];`
483	`} else {`	478	`} else {`
484	`*delstdin = 0;`	479	`*delstdin = 0;`
485	`}`	480	`}`
486	`}`	481	`}`
487		482
488	`/* same for stdout file */`	483	`/* same for stdout file */`
489	`if (redir->stdoutfile) {`	484	`if (redir->stdoutfile) {`
490	`char far *farptr = MK_FP(rmod->rmodseg, RMOD_OFFSET_STDOUTFILE);`	485	`char far *farptr = MK_FP(rmod->rmodseg, RMOD_OFFSET_STDOUTFILE);`
491	`unsigned short far *farptr16 = MK_FP(rmod->rmodseg, RMOD_OFFSET_STDOUTAPP);`	486	`unsigned short far *farptr16 = MK_FP(rmod->rmodseg, RMOD_OFFSET_STDOUTAPP);`
492	`_fstrcpy(farptr, redir->stdoutfile);`	487	`_fstrcpy(farptr, redir->stdoutfile);`
493	`/* openflag */`	488	`/* openflag */`
494	`*farptr16 = redir->stdout_openflag;`	489	`*farptr16 = redir->stdout_openflag;`
495	`}`	490	`}`
496		491
497	`/* copy cmdtail to rmod's PSP and compute its len */`	492	`/* copy cmdtail to rmod's PSP and compute its len */`
498	`for (i = 0; cmdtail[i] != 0; i++) rmod_cmdtail[i] = cmdtail[i];`	493	`for (i = 0; cmdtail[i] != 0; i++) rmod_cmdtail[i] = cmdtail[i];`
499	`rmod_cmdtail[i] = '\r';`	494	`rmod_cmdtail[i] = '\r';`
500	`rmod_cmdtail[-1] = i;`	495	`rmod_cmdtail[-1] = i;`

Subversion Repositories SvarDOS

(root)/svarcom/trunk/command.c – Rev 960 → 963