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 */
 
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);
}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
static void run_as_external(char *buff, const char *cmdline, unsigned short envseg, struct rmod_props far *rmod, struct redir_data *redir) {
  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"))) {
    /* copy truename of the bat file to rmod buff */
    _fstrcpy(rmod->batfile, cmdfile);
 
    /* explode args of the bat file and store them in rmod buff */
    cmd_explode(buff, cmdline, NULL);
    _fmemcpy(rmod->batargv, buff, sizeof(rmod->batargv));
 
    /* reset the 'next line to execute' counter */
    rmod->batnextline = 0;
    /* remember the echo flag (in case bat file disables echo) */
    rmod->flags &= ~FLAG_ECHO_BEFORE_BAT;
    if (rmod->flags & FLAG_ECHOFLAG) rmod->flags |= FLAG_ECHO_BEFORE_BAT;
    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);
    _fstrcpy(farptr, redir->stdinfile);
  }
 
  /* 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->batfile);
  unsigned short batname_off = FP_OFF(rmod->batfile);
  unsigned short filepos_cx = rmod->batnextline >> 16;
  unsigned short filepos_dx = rmod->batnextline & 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->batnextline += 1;
      break;
    }
  }
  buff[i] = 0;
  rmod->batnextline += i + 1;
 
  return(0);
 
  OOPS:
  rmod->batfile[0] = 0;
  rmod->batnextline = 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 = rmod->batargv;
 
      /* 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 */
 
  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); */
  } 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);
  }
 
  /* 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->batfile[0] == 0)) outputnl("");
 
    SKIP_NEWLINE:
 
    /* cancel any redirections that may have been set up before */
    redir_revert();
 
    /* 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;
      goto EXEC_CMDLINE;
    }
 
    /* 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->batfile[0] != 0) {
      if (getbatcmd(BUFFER, CMDLINE_MAXLEN, rmod) != 0) { /* end of batch */
        /* restore echo flag as it was before running the bat file */
        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++;
      /* 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);
    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);
    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_NOTFOUND) {
      /* this was not an internal command, try matching an external command */
      run_as_external(BUFFER, cmdline, *rmod_envseg, rmod, &redirprops);
      /* perhaps this is a newly launched BAT file */
      if ((rmod->batfile[0] != 0) && (rmod->batnextline == 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");
 
  } while ((rmod->flags & FLAG_EXEC_AND_QUIT) == 0);
 
  sayonara(rmod);
  return(0);
}
 

Rev 548	Rev 571
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 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	`struct config {`	42	`struct config {`
43	`unsigned char flags; /* command.com flags, as defined in rmodinit.h */`	43	`unsigned char flags; /* command.com flags, as defined in rmodinit.h */`
44	`char *execcmd;`	44	`char *execcmd;`
45	`unsigned short envsiz;`	45	`unsigned short envsiz;`
46	`};`	46	`};`
47		47
48	`/* max length of the cmdline storage (bytes) - includes also max length of`	48	`/* max length of the cmdline storage (bytes) - includes also max length of`
49	`* line loaded from a BAT file (no more than 255 bytes!) */`	49	`* line loaded from a BAT file (no more than 255 bytes!) */`
50	`#define CMDLINE_MAXLEN 255`	50	`#define CMDLINE_MAXLEN 255`
51		51
52		52
53	`/* sets guard values at a few places in memory for later detection of`	53	`/* sets guard values at a few places in memory for later detection of`
54	`* overflows via memguard_check() */`	54	`* overflows via memguard_check() */`
55	`static void memguard_set(char *cmdlinebuf) {`	55	`static void memguard_set(char *cmdlinebuf) {`
56	`BUFFER[sizeof(BUFFER) - 1] = 0xC7;`	56	`BUFFER[sizeof(BUFFER) - 1] = 0xC7;`
57	`cmdlinebuf[CMDLINE_MAXLEN] = 0xC7;`	57	`cmdlinebuf[CMDLINE_MAXLEN] = 0xC7;`
58	`}`	58	`}`
59		59
60		60
61	`/* checks for valguards at specific memory locations, returns 0 on success */`	61	`/* checks for valguards at specific memory locations, returns 0 on success */`
62	`static int memguard_check(unsigned short rmodseg, char *cmdlinebuf) {`	62	`static int memguard_check(unsigned short rmodseg, char *cmdlinebuf) {`
63	`/* check RMOD signature (would be overwritten in case of stack overflow */`	63	`/* check RMOD signature (would be overwritten in case of stack overflow */`
64	`static char msg[] = "!! MEMORY CORRUPTION ## DETECTED !!";`	64	`static char msg[] = "!! MEMORY CORRUPTION ## DETECTED !!";`
65	`unsigned short far *rmodsig = MK_FP(rmodseg, 0x100 + 6);`	65	`unsigned short far *rmodsig = MK_FP(rmodseg, 0x100 + 6);`
66	`unsigned char far *rmod = MK_FP(rmodseg, 0);`	66	`unsigned char far *rmod = MK_FP(rmodseg, 0);`
67		67
68	`if (*rmodsig != 0x2019) {`	68	`if (*rmodsig != 0x2019) {`
69	`msg[22] = '1';`	69	`msg[22] = '1';`
70	`goto FAIL;`	70	`goto FAIL;`
71	`}`	71	`}`
72		72
73	`/* check last BUFFER byte */`	73	`/* check last BUFFER byte */`
74	`if (BUFFER[sizeof(BUFFER) - 1] != 0xC7) {`	74	`if (BUFFER[sizeof(BUFFER) - 1] != 0xC7) {`
75	`msg[22] = '2';`	75	`msg[22] = '2';`
76	`goto FAIL;`	76	`goto FAIL;`
77	`}`	77	`}`
78		78
79	`/* check last cmdlinebuf byte */`	79	`/* check last cmdlinebuf byte */`
80	`if (cmdlinebuf[CMDLINE_MAXLEN] != 0xC7) {`	80	`if (cmdlinebuf[CMDLINE_MAXLEN] != 0xC7) {`
81	`msg[22] = '3';`	81	`msg[22] = '3';`
82	`goto FAIL;`	82	`goto FAIL;`
83	`}`	83	`}`
84		84
85	`/* check rmod exec buf */`	85	`/* check rmod exec buf */`
86	`if (rmod[RMOD_OFFSET_EXECPROG + 127] != 0) {`	86	`if (rmod[RMOD_OFFSET_EXECPROG + 127] != 0) {`
87	`msg[22] = '4';`	87	`msg[22] = '4';`
88	`goto FAIL;`	88	`goto FAIL;`
89	`}`	89	`}`
90		90
91	`/* check rmod exec stdin buf */`	91	`/* check rmod exec stdin buf */`
92	`if (rmod[RMOD_OFFSET_STDINFILE + 127] != 0) {`	92	`if (rmod[RMOD_OFFSET_STDINFILE + 127] != 0) {`
93	`msg[22] = '5';`	93	`msg[22] = '5';`
94	`goto FAIL;`	94	`goto FAIL;`
95	`}`	95	`}`
96		96
97	`/* check rmod exec stdout buf */`	97	`/* check rmod exec stdout buf */`
98	`if (rmod[RMOD_OFFSET_STDOUTFILE + 127] != 0) {`	98	`if (rmod[RMOD_OFFSET_STDOUTFILE + 127] != 0) {`
99	`msg[22] = '6';`	99	`msg[22] = '6';`
100	`goto FAIL;`	100	`goto FAIL;`
101	`}`	101	`}`
102		102
103	`/* else all good */`	103	`/* else all good */`
104	`return(0);`	104	`return(0);`
105		105
106	`/* error handling */`	106	`/* error handling */`
107	`FAIL:`	107	`FAIL:`
108	`outputnl(msg);`	108	`outputnl(msg);`
109	`return(1);`	109	`return(1);`
110	`}`	110	`}`
111		111
112		112
113	`/* parses command line the hard way (directly from PSP) */`	113	`/* parses command line the hard way (directly from PSP) */`
114	`static void parse_argv(struct config *cfg) {`	114	`static void parse_argv(struct config *cfg) {`
115	`const unsigned char cmdlinelen = (void )0x80;`	115	`const unsigned char cmdlinelen = (void )0x80;`
116	`char cmdline = (void )0x81;`	116	`char cmdline = (void )0x81;`
117		117
118	`memset(cfg, 0, sizeof(*cfg));`	118	`memset(cfg, 0, sizeof(*cfg));`
119		119
120	`/* set a NULL terminator on cmdline */`	120	`/* set a NULL terminator on cmdline */`
121	`cmdline[*cmdlinelen] = 0;`	121	`cmdline[*cmdlinelen] = 0;`
122		122
123	`while (*cmdline != 0) {`	123	`while (*cmdline != 0) {`
124		124
125	`/* skip over any leading spaces */`	125	`/* skip over any leading spaces */`
126	`if (*cmdline == ' ') {`	126	`if (*cmdline == ' ') {`
127	`cmdline++;`	127	`cmdline++;`
128	`continue;`	128	`continue;`
129	`}`	129	`}`
130		130
131	`if (*cmdline != '/') {`	131	`if (*cmdline != '/') {`
132	`output("Invalid parameter: ");`	132	`output("Invalid parameter: ");`
133	`outputnl(cmdline);`	133	`outputnl(cmdline);`
134	`goto SKIP_TO_NEXT_ARG;`	134	`goto SKIP_TO_NEXT_ARG;`
135	`}`	135	`}`
136		136
137	`/* got a slash */`	137	`/* got a slash */`
138	`cmdline++; /* skip the slash */`	138	`cmdline++; /* skip the slash */`
139	`switch (*cmdline) {`	139	`switch (*cmdline) {`
140	`case 'c': /* /C = execute command and quit */`	140	`case 'c': /* /C = execute command and quit */`
141	`case 'C':`	141	`case 'C':`
142	`cfg->flags \|= FLAG_EXEC_AND_QUIT;`	142	`cfg->flags \|= FLAG_EXEC_AND_QUIT;`
143	`/* FALLTHRU */`	143	`/* FALLTHRU */`
144	`case 'k': /* /K = execute command and keep running */`	144	`case 'k': /* /K = execute command and keep running */`
145	`case 'K':`	145	`case 'K':`
146	`cfg->execcmd = cmdline + 1;`	146	`cfg->execcmd = cmdline + 1;`
147	`return;`	147	`return;`
148		148
149	`case 'd': /* /D = skip autoexec.bat processing */`	149	`case 'd': /* /D = skip autoexec.bat processing */`
150	`case 'D':`	150	`case 'D':`
151	`cfg->flags \|= FLAG_SKIP_AUTOEXEC;`	151	`cfg->flags \|= FLAG_SKIP_AUTOEXEC;`
152	`break;`	152	`break;`
153		153
154	`case 'e': /* preset the initial size of the environment block */`	154	`case 'e': /* preset the initial size of the environment block */`
155	`case 'E':`	155	`case 'E':`
156	`cmdline++;`	156	`cmdline++;`
157	`if (cmdline == ':') cmdline++; / could be /E:size */`	157	`if (cmdline == ':') cmdline++; / could be /E:size */`
158	`atous(&(cfg->envsiz), cmdline);`	158	`atous(&(cfg->envsiz), cmdline);`
159	`if (cfg->envsiz < 64) cfg->envsiz = 0;`	159	`if (cfg->envsiz < 64) cfg->envsiz = 0;`
160	`break;`	160	`break;`
161		161
162	`case 'p': /* permanent shell (can't exit + run autoexec.bat) */`	162	`case 'p': /* permanent shell (can't exit + run autoexec.bat) */`
163	`case 'P':`	163	`case 'P':`
164	`cfg->flags \|= FLAG_PERMANENT;`	164	`cfg->flags \|= FLAG_PERMANENT;`
165	`break;`	165	`break;`
166		166
167	`case '?':`	167	`case '?':`
168	`outputnl("Starts the SvarCOM command interpreter");`	168	`outputnl("Starts the SvarCOM command interpreter");`
169	`outputnl("");`	169	`outputnl("");`
170	`outputnl("COMMAND /E:nnn [/[C\|K] [/P] [/D] command]");`	170	`outputnl("COMMAND /E:nnn [/[C\|K] [/P] [/D] command]");`
171	`outputnl("");`	171	`outputnl("");`
172	`outputnl("/D Skip AUTOEXEC.BAT processing (makes sense only with /P)");`	172	`outputnl("/D Skip AUTOEXEC.BAT processing (makes sense only with /P)");`
173	`outputnl("/E:nnn Sets the environment size to nnn bytes");`	173	`outputnl("/E:nnn Sets the environment size to nnn bytes");`
174	`outputnl("/P Makes the new command interpreter permanent and run AUTOEXEC.BAT");`	174	`outputnl("/P Makes the new command interpreter permanent and run AUTOEXEC.BAT");`
175	`outputnl("/C Executes the specified command and returns");`	175	`outputnl("/C Executes the specified command and returns");`
176	`outputnl("/K Executes the specified command and continues running");`	176	`outputnl("/K Executes the specified command and continues running");`
177	`exit(1);`	177	`exit(1);`
178	`break;`	178	`break;`
179		179
180	`default:`	180	`default:`
181	`output("Invalid switch: /");`	181	`output("Invalid switch: /");`
182	`outputnl(cmdline);`	182	`outputnl(cmdline);`
183	`break;`	183	`break;`
184	`}`	184	`}`
185		185
186	`/* move to next argument or quit processing if end of cmdline */`	186	`/* move to next argument or quit processing if end of cmdline */`
187	`SKIP_TO_NEXT_ARG:`	187	`SKIP_TO_NEXT_ARG:`
188	`while ((cmdline != 0) && (cmdline != ' ') && (*cmdline != '/')) cmdline++;`	188	`while ((cmdline != 0) && (cmdline != ' ') && (*cmdline != '/')) cmdline++;`
189	`}`	189	`}`
190	`}`	190	`}`
191		191
192		192
193	`/* builds the prompt string and displays it. buff is filled with a zero-terminated copy of the prompt. */`	193	`/* builds the prompt string and displays it. buff is filled with a zero-terminated copy of the prompt. */`
194	`static void build_and_display_prompt(char *buff, unsigned short envseg) {`	194	`static void build_and_display_prompt(char *buff, unsigned short envseg) {`
195	`char *s = buff;`	195	`char *s = buff;`
196	`/* locate the prompt variable or use the default pattern */`	196	`/* locate the prompt variable or use the default pattern */`
197	`const char far *fmt = env_lookup_val(envseg, "PROMPT");`	197	`const char far *fmt = env_lookup_val(envseg, "PROMPT");`
198	`if ((fmt == NULL) \|\| (fmt == 0)) fmt = "$p$g"; / fallback to default if empty */`	198	`if ((fmt == NULL) \|\| (fmt == 0)) fmt = "$p$g"; / fallback to default if empty */`
199	`/* build the prompt string based on pattern */`	199	`/* build the prompt string based on pattern */`
200	`for (; *fmt != 0; fmt++) {`	200	`for (; *fmt != 0; fmt++) {`
201	`if (*fmt != '$') {`	201	`if (*fmt != '$') {`
202	`s = fmt;`	202	`s = fmt;`
203	`s++;`	203	`s++;`
204	`continue;`	204	`continue;`
205	`}`	205	`}`
206	`/* escape code ($P, etc) */`	206	`/* escape code ($P, etc) */`
207	`fmt++;`	207	`fmt++;`
208	`switch (*fmt) {`	208	`switch (*fmt) {`
209	`case 'Q': /* $Q = = (equal sign) */`	209	`case 'Q': /* $Q = = (equal sign) */`
210	`case 'q':`	210	`case 'q':`
211	`*s = '=';`	211	`*s = '=';`
212	`s++;`	212	`s++;`
213	`break;`	213	`break;`
214	`case '$': /* $$ = $ (dollar sign) */`	214	`case '$': /* $$ = $ (dollar sign) */`
215	`*s = '$';`	215	`*s = '$';`
216	`s++;`	216	`s++;`
217	`break;`	217	`break;`
218	`case 'T': /* $t = current time */`	218	`case 'T': /* $t = current time */`
219	`case 't':`	219	`case 't':`
220	`s += sprintf(s, "00:00"); /* TODO */`	220	`s += sprintf(s, "00:00"); /* TODO */`
221	`break;`	221	`break;`
222	`case 'D': /* $D = current date */`	222	`case 'D': /* $D = current date */`
223	`case 'd':`	223	`case 'd':`
224	`s += sprintf(s, "1985-07-29"); /* TODO */`	224	`s += sprintf(s, "1985-07-29"); /* TODO */`
225	`break;`	225	`break;`
226	`case 'P': /* $P = current drive and path */`	226	`case 'P': /* $P = current drive and path */`
227	`case 'p':`	227	`case 'p':`
228	`_asm {`	228	`_asm {`
229	`mov ah, 0x19 /* DOS 1+ - GET CURRENT DRIVE */`	229	`mov ah, 0x19 /* DOS 1+ - GET CURRENT DRIVE */`
230	`int 0x21`	230	`int 0x21`
231	`mov bx, s`	231	`mov bx, s`
232	`mov [bx], al /* AL = drive (00 = A:, 01 = B:, etc */`	232	`mov [bx], al /* AL = drive (00 = A:, 01 = B:, etc */`
233	`}`	233	`}`
234	`*s += 'A';`	234	`*s += 'A';`
235	`s++;`	235	`s++;`
236	`*s = ':';`	236	`*s = ':';`
237	`s++;`	237	`s++;`
238	`*s = '\\';`	238	`*s = '\\';`
239	`s++;`	239	`s++;`
240	`_asm {`	240	`_asm {`
241	`mov ah, 0x47 /* DOS 2+ - CWD - GET CURRENT DIRECTORY */`	241	`mov ah, 0x47 /* DOS 2+ - CWD - GET CURRENT DIRECTORY */`
242	`xor dl,dl /* DL = drive number (00h = default, 01h = A:, etc) */`	242	`xor dl,dl /* DL = drive number (00h = default, 01h = A:, etc) */`
243	`mov si, s /* DS:SI -> 64-byte buffer for ASCIZ pathname */`	243	`mov si, s /* DS:SI -> 64-byte buffer for ASCIZ pathname */`
244	`int 0x21`	244	`int 0x21`
245	`jc DONE /* leave path empty on error */`	245	`jc DONE /* leave path empty on error */`
246	`/* move s ptr forward to end (0-termintor) of pathname */`	246	`/* move s ptr forward to end (0-termintor) of pathname */`
247	`NEXTBYTE:`	247	`NEXTBYTE:`
248	`mov si, s`	248	`mov si, s`
249	`cmp byte ptr [si], 0`	249	`cmp byte ptr [si], 0`
250	`je DONE`	250	`je DONE`
251	`inc s`	251	`inc s`
252	`jmp NEXTBYTE`	252	`jmp NEXTBYTE`
253	`DONE:`	253	`DONE:`
254	`}`	254	`}`
255	`break;`	255	`break;`
256	`case 'V': /* $V = DOS version number */`	256	`case 'V': /* $V = DOS version number */`
257	`case 'v':`	257	`case 'v':`
258	`s += sprintf(s, "VER"); /* TODO */`	258	`s += sprintf(s, "VER"); /* TODO */`
259	`break;`	259	`break;`
260	`case 'N': /* $N = current drive */`	260	`case 'N': /* $N = current drive */`
261	`case 'n':`	261	`case 'n':`
262	`_asm {`	262	`_asm {`
263	`mov ah, 0x19 /* DOS 1+ - GET CURRENT DRIVE */`	263	`mov ah, 0x19 /* DOS 1+ - GET CURRENT DRIVE */`
264	`int 0x21`	264	`int 0x21`
265	`mov bx, s`	265	`mov bx, s`
266	`mov [bx], al /* AL = drive (00 = A:, 01 = B:, etc */`	266	`mov [bx], al /* AL = drive (00 = A:, 01 = B:, etc */`
267	`}`	267	`}`
268	`*s += 'A';`	268	`*s += 'A';`
269	`s++;`	269	`s++;`
270	`break;`	270	`break;`
271	`case 'G': /* $G = > (greater-than sign) */`	271	`case 'G': /* $G = > (greater-than sign) */`
272	`case 'g':`	272	`case 'g':`
273	`*s = '>';`	273	`*s = '>';`
274	`s++;`	274	`s++;`
275	`break;`	275	`break;`
276	`case 'L': /* $L = < (less-than sign) */`	276	`case 'L': /* $L = < (less-than sign) */`
277	`case 'l':`	277	`case 'l':`
278	`*s = '<';`	278	`*s = '<';`
279	`s++;`	279	`s++;`
280	`break;`	280	`break;`
281	`case 'B': /* $B = \| (pipe) */`	281	`case 'B': /* $B = \| (pipe) */`
282	`case 'b':`	282	`case 'b':`
283	`*s = '\|';`	283	`*s = '\|';`
284	`s++;`	284	`s++;`
285	`break;`	285	`break;`
286	`case 'H': /* $H = backspace (erases previous character) */`	286	`case 'H': /* $H = backspace (erases previous character) */`
287	`case 'h':`	287	`case 'h':`
288	`*s = '\b';`	288	`*s = '\b';`
289	`s++;`	289	`s++;`
290	`break;`	290	`break;`
291	`case 'E': /* $E = Escape code (ASCII 27) */`	291	`case 'E': /* $E = Escape code (ASCII 27) */`
292	`case 'e':`	292	`case 'e':`
293	`*s = 27;`	293	`*s = 27;`
294	`s++;`	294	`s++;`
295	`break;`	295	`break;`
296	`case '_': /* $_ = CR+LF */`	296	`case '_': /* $_ = CR+LF */`
297	`*s = '\r';`	297	`*s = '\r';`
298	`s++;`	298	`s++;`
299	`*s = '\n';`	299	`*s = '\n';`
300	`s++;`	300	`s++;`
301	`break;`	301	`break;`
302	`}`	302	`}`
303	`}`	303	`}`
304	`*s = 0;`	304	`*s = 0;`
305	`output(buff);`	305	`output(buff);`
306	`}`	306	`}`
307		307
308		308
309	`/* tries locating executable fname in path and fill res with result. returns 0 on success,`	-
310	`* -1 on failed match and -2 on failed match + "don't even try with other paths"`	-
311	`* extptr contains a ptr to the extension in fname (NULL if not found) */`	-
312	`static int lookup_cmd(char res, const char fname, const char path, const char *extptr) {`	-
313	`unsigned short lastbslash = 0;`	-
314	`unsigned short i, len;`	-
315	`unsigned char explicitpath = 0;`	-
316		-
317	`/* does the original fname has an explicit path prefix or explicit ext? */`	-
318	`*extptr = NULL;`	-
319	`for (i = 0; fname[i] != 0; i++) {`	-
320	`switch (fname[i]) {`	-
321	`case ':':`	-
322	`case '\\':`	-
323	`explicitpath = 1;`	-
324	`extptr = NULL; / extension is the last dot AFTER all path delimiters */`	-
325	`break;`	-
326	`case '.':`	-
327	`*extptr = fname + i + 1;`	-
328	`break;`	-
329	`}`	-
330	`}`	-
331		-
332	`/* normalize filename */`	-
333	`if (file_truename(fname, res) != 0) return(-2);`	-
334		-
335	`/* printf("truename: %s\r\n", res); */`	-
336		-
337	`/* figure out where the command starts and if it has an explicit extension */`	-
338	`for (len = 0; res[len] != 0; len++) {`	-
339	`switch (res[len]) {`	-
340	`case '?': /* abort on any wildcard character */`	-
341	`case '*':`	-
342	`return(-2);`	-
343	`case '\\':`	-
344	`lastbslash = len;`	-
345	`break;`	-
346	`}`	-
347	`}`	-
348		-
349	`/* printf("lastbslash=%u\r\n", lastbslash); */`	-
350		-
351	`/* if no path prefix was found in fname (no colon or backslash) AND we have`	-
352	`* a path arg, then assemble path+filename */`	-
353	`if ((!explicitpath) && (path != NULL) && (path[0] != 0)) {`	-
354	`i = strlen(path);`	-
355	`if (path[i - 1] != '\\') i++; /* add a byte for inserting a bkslash after path */`	-
356	`/* move the filename at the place where path will end */`	-
357	`memmove(res + i, res + lastbslash + 1, len - lastbslash);`	-
358	`/* copy path in front of the filename and make sure there is a bkslash sep */`	-
359	`memmove(res, path, i);`	-
360	`res[i - 1] = '\\';`	-
361	`}`	-
362		-
363	`/* if no extension was initially provided, try matching COM, EXE, BAT */`	-
364	`if (*extptr == NULL) {`	-
365	`const char *ext[] = {".COM", ".EXE", ".BAT", NULL};`	-
366	`len = strlen(res);`	-
367	`for (i = 0; ext[i] != NULL; i++) {`	-
368	`strcpy(res + len, ext[i]);`	-
369	`/* printf("? '%s'\r\n", res); */`	-
370	`*extptr = ext[i] + 1;`	-
371	`if (file_getattr(res) >= 0) return(0);`	-
372	`}`	-
373	`} else { /* try finding it as-is */`	-
374	`/* printf("? '%s'\r\n", res); */`	-
375	`if (file_getattr(res) >= 0) return(0);`	-
376	`}`	-
377		-
378	`/* not found */`	-
379	`if (explicitpath) return(-2); /* don't bother trying other paths, the caller had its own path preset anyway */`	-
380	`return(-1);`	-
381	`}`	-
382		-
383		-
384	`static void run_as_external(char buff, const char cmdline, unsigned short envseg, struct rmod_props far rmod, struct redir_data redir) {`	309	`static void run_as_external(char buff, const char cmdline, unsigned short envseg, struct rmod_props far rmod, struct redir_data redir) {`
385	`char *cmdfile = buff + 512;`	310	`char *cmdfile = buff + 512;`
386	`const char far *pathptr;`	311	`const char far *pathptr;`
387	`int lookup;`	312	`int lookup;`
388	`unsigned short i;`	313	`unsigned short i;`
389	`const char *ext;`	314	`const char *ext;`
390	`char *cmd = buff + 1024;`	315	`char *cmd = buff + 1024;`
391	`const char *cmdtail;`	316	`const char *cmdtail;`
392	`char far *rmod_execprog = MK_FP(rmod->rmodseg, RMOD_OFFSET_EXECPROG);`	317	`char far *rmod_execprog = MK_FP(rmod->rmodseg, RMOD_OFFSET_EXECPROG);`
393	`char far *rmod_cmdtail = MK_FP(rmod->rmodseg, 0x81);`	318	`char far *rmod_cmdtail = MK_FP(rmod->rmodseg, 0x81);`
394	`_Packed struct {`	319	`_Packed struct {`
395	`unsigned short envseg;`	320	`unsigned short envseg;`
396	`unsigned long cmdtail;`	321	`unsigned long cmdtail;`
397	`unsigned long fcb1;`	322	`unsigned long fcb1;`
398	`unsigned long fcb2;`	323	`unsigned long fcb2;`
399	`} far *ExecParam = MK_FP(rmod->rmodseg, RMOD_OFFSET_EXECPARAM);`	324	`} far *ExecParam = MK_FP(rmod->rmodseg, RMOD_OFFSET_EXECPARAM);`
400		325
401	`/* find cmd and cmdtail */`	326	`/* find cmd and cmdtail */`
402	`i = 0;`	327	`i = 0;`
403	`cmdtail = cmdline;`	328	`cmdtail = cmdline;`
404	`while (cmdtail == ' ') cmdtail++; / skip any leading spaces */`	329	`while (cmdtail == ' ') cmdtail++; / skip any leading spaces */`
405	`while ((cmdtail != ' ') && (cmdtail != '/') && (cmdtail != '+') && (cmdtail != 0)) {`	330	`while ((cmdtail != ' ') && (cmdtail != '/') && (cmdtail != '+') && (cmdtail != 0)) {`
406	`cmd[i++] = *cmdtail;`	331	`cmd[i++] = *cmdtail;`
407	`cmdtail++;`	332	`cmdtail++;`
408	`}`	333	`}`
409	`cmd[i] = 0;`	334	`cmd[i] = 0;`
410		335
411	`/* is this a command in curdir? */`	336	`/* is this a command in curdir? */`
412	`lookup = lookup_cmd(cmdfile, cmd, NULL, &ext);`	337	`lookup = lookup_cmd(cmdfile, cmd, NULL, &ext);`
413	`if (lookup == 0) {`	338	`if (lookup == 0) {`
414	`/* printf("FOUND LOCAL EXEC FILE: '%s'\r\n", cmdfile); */`	339	`/* printf("FOUND LOCAL EXEC FILE: '%s'\r\n", cmdfile); */`
415	`goto RUNCMDFILE;`	340	`goto RUNCMDFILE;`
416	`} else if (lookup == -2) {`	341	`} else if (lookup == -2) {`
417	`/* puts("NOT FOUND"); */`	342	`/* puts("NOT FOUND"); */`
418	`return;`	343	`return;`
419	`}`	344	`}`
420		345
421	`/* try matching something in PATH */`	346	`/* try matching something in PATH */`
422	`pathptr = env_lookup_val(envseg, "PATH");`	347	`pathptr = env_lookup_val(envseg, "PATH");`
423	`if (pathptr == NULL) return;`	-
424		348
425	`/* try each path in %PATH% */`	349	`/* try each path in %PATH% */`
426	`for (;;) {`	350	`while (pathptr) {`
427	`for (i = 0;; i++) {`	351	`for (i = 0;; i++) {`
428	`buff[i] = *pathptr;`	352	`buff[i] = *pathptr;`
429	`if ((buff[i] == 0) \|\| (buff[i] == ';')) break;`	353	`if ((buff[i] == 0) \|\| (buff[i] == ';')) break;`
430	`pathptr++;`	354	`pathptr++;`
431	`}`	355	`}`
432	`buff[i] = 0;`	356	`buff[i] = 0;`
433	`lookup = lookup_cmd(cmdfile, cmd, buff, &ext);`	357	`lookup = lookup_cmd(cmdfile, cmd, buff, &ext);`
434	`if (lookup == 0) break;`	358	`if (lookup == 0) goto RUNCMDFILE;`
435	`if (lookup == -2) return;`	359	`if (lookup == -2) return;`
436	`if (*pathptr == ';') {`	360	`if (*pathptr == ';') {`
437	`pathptr++;`	361	`pathptr++;`
438	`} else {`	362	`} else {`
439	`return;`	363	`break;`
440	`}`	364	`}`
441	`}`	365	`}`
442		366
-		367	`/* last chance: is it an executable link? (trim extension from cmd first) */`
-		368	`for (i = 0; (cmd[i] != 0) && (cmd[i] != '.') && (i < 9); i++) buff[128 + i] = cmd[i];`
-		369	`buff[128 + i] = 0;`
-		370	`if ((i < 9) && (link_computefname(buff, buff + 128, envseg) == 0)) {`
-		371	`/* try opening the link file (if it exists) and read it into buff */`
-		372	`i = 0;`
-		373	`_asm {`
-		374	`push ax`
-		375	`push bx`
-		376	`push cx`
-		377	`push dx`
-		378
-		379	`mov ax, 0x3d00 /* DOS 2+ - OPEN EXISTING FILE, READ-ONLY */`
-		380	`mov dx, buff /* file name */`
-		381	`int 0x21`
-		382	`jc ERR_FOPEN`
-		383	`/* file handle in AX, read from file now */`
-		384	`mov bx, ax /* file handle */`
-		385	`mov ah, 0x3f /* Read from file via handle bx */`
-		386	`mov cx, 128 /* up to 128 bytes */`
-		387	`/* mov dx, buff / / dest buffer (already set) */`
-		388	`int 0x21 /* read up to 256 bytes from file and write to buff */`
-		389	`jc ERR_READ`
-		390	`mov i, ax`
-		391	`ERR_READ:`
-		392	`mov ah, 0x3e /* close file handle in BX */`
-		393	`int 0x21`
-		394	`ERR_FOPEN:`
-		395
-		396	`pop dx`
-		397	`pop cx`
-		398	`pop bx`
-		399	`pop ax`
-		400	`}`
-		401
-		402	`/* did I read anything? */`
-		403	`if (i != 0) {`
-		404	`buff[i] = 0;`
-		405	`/* trim buff at first \n or \r, just in case someone fiddled with the`
-		406	`* link file using a text editor */`
-		407	`for (i = 0; (buff[i] != 0) && (buff[i] != '\r') && (buff[i] != '\n'); i++);`
-		408	`buff[i] = 0;`
-		409	`/* lookup check */`
-		410	`if (buff[0] != 0) {`
-		411	`lookup = lookup_cmd(cmdfile, cmd, buff, &ext);`
-		412	`if (lookup == 0) goto RUNCMDFILE;`
-		413	`}`
-		414	`}`
-		415	`}`
-		416
-		417	`/* all failed (ie. executable file not found) */`
-		418	`return;`
-		419
443	`RUNCMDFILE:`	420	`RUNCMDFILE:`
444		421
445	`/* special handling of batch files */`	422	`/* special handling of batch files */`
446	`if ((ext != NULL) && (imatch(ext, "bat"))) {`	423	`if ((ext != NULL) && (imatch(ext, "bat"))) {`
447	`/* copy truename of the bat file to rmod buff */`	424	`/* copy truename of the bat file to rmod buff */`

Subversion Repositories SvarDOS

(root)/svarcom/trunk/command.c – Rev 548 → 571