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 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);
  if (*rmodsig != 0x2019) {
    msg[22] = '1';
    outputnl(msg);
    printf("rmodseg = %04X ; *rmodsig = %04X\r\n", rmodseg, *rmodsig);
    return(1);
  }
  /* check last BUFFER byte */
  if (BUFFER[sizeof(BUFFER) - 1] != 0xC7) {
    msg[22] = '2';
    outputnl(msg);
    return(2);
  }
  /* check last cmdlinebuf byte */
  if (cmdlinebuf[CMDLINE_MAXLEN] != 0xC7) {
    msg[22] = '3';
    outputnl(msg);
    return(3);
  }
  /* all good */
  return(0);
}
 
 
/* 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);
}
 
 
/* tries locating executable fname in path and fill res with result. returns 0 on success,
 * -1 on failed match and -2 on failed match + "don't even try with other paths"
 * extptr contains a ptr to the extension in fname (NULL if not found) */
static int lookup_cmd(char *res, const char *fname, const char *path, const char **extptr) {
  unsigned short lastbslash = 0;
  unsigned short i, len;
  unsigned char explicitpath = 0;
 
  /* does the original fname has an explicit path prefix or explicit ext? */
  *extptr = NULL;
  for (i = 0; fname[i] != 0; i++) {
    switch (fname[i]) {
      case ':':
      case '\\':
        explicitpath = 1;
        *extptr = NULL; /* extension is the last dot AFTER all path delimiters */
        break;
      case '.':
        *extptr = fname + i + 1;
        break;
    }
  }
 
  /* normalize filename */
  if (file_truename(fname, res) != 0) return(-2);
 
  /* printf("truename: %s\r\n", res); */
 
  /* figure out where the command starts and if it has an explicit extension */
  for (len = 0; res[len] != 0; len++) {
    switch (res[len]) {
      case '?':   /* abort on any wildcard character */
      case '*':
        return(-2);
      case '\\':
        lastbslash = len;
        break;
    }
  }
 
  /* printf("lastbslash=%u\r\n", lastbslash); */
 
  /* if no path prefix was found in fname (no colon or backslash) AND we have
   * a path arg, then assemble path+filename */
  if ((!explicitpath) && (path != NULL) && (path[0] != 0)) {
    i = strlen(path);
    if (path[i - 1] != '\\') i++; /* add a byte for inserting a bkslash after path */
    /* move the filename at the place where path will end */
    memmove(res + i, res + lastbslash + 1, len - lastbslash);
    /* copy path in front of the filename and make sure there is a bkslash sep */
    memmove(res, path, i);
    res[i - 1] = '\\';
  }
 
  /* if no extension was initially provided, try matching COM, EXE, BAT */
  if (*extptr == NULL) {
    const char *ext[] = {".COM", ".EXE", ".BAT", NULL};
    len = strlen(res);
    for (i = 0; ext[i] != NULL; i++) {
      strcpy(res + len, ext[i]);
      /* printf("? '%s'\r\n", res); */
      *extptr = ext[i] + 1;
      if (file_getattr(res) >= 0) return(0);
    }
  } else { /* try finding it as-is */
    /* printf("? '%s'\r\n", res); */
    if (file_getattr(res) >= 0) return(0);
  }
 
  /* not found */
  if (explicitpath) return(-2); /* don't bother trying other paths, the caller had its own path preset anyway */
  return(-1);
}
 
 
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");
  if (pathptr == NULL) return;
 
  /* try each path in %PATH% */
  for (;;) {
    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) break;
    if (lookup == -2) return;
    if (*pathptr == ';') {
      pathptr++;
    } else {
      return;
    }
  }
 
  RUNCMDFILE:
 
  /* special handling of batch files */
  if ((ext != NULL) && (imatch(ext, "bat"))) {
    /* copy truename of the bat file to rmod buff */
    for (i = 0; cmdfile[i] != 0; i++) rmod->batfile[i] = cmdfile[i];
    rmod->batfile[i] = 0;
 
    /* 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) */
  for (i = 0; cmdfile[i] != 0; i++) rmod_execprog[i] = cmdfile[i];
  rmod_execprog[i++] = 0;
  if (redir->stdinfile) {
    unsigned short far *farptr = MK_FP(rmod->rmodseg, RMOD_OFFSET_STDINFILE);
    unsigned short t;
    *farptr = i;
    for (t = 0;; t++) {
      rmod_execprog[i++] = redir->stdinfile[t];
      if (redir->stdinfile[t] == 0) break;
    }
  }
  if (redir->stdoutfile) {
    unsigned short far *farptr = MK_FP(rmod->rmodseg, RMOD_OFFSET_STDOUTFILE);
    unsigned short t;
    *farptr = i;
    for (t = 0;; t++) {
      rmod_execprog[i++] = redir->stdoutfile[t];
      if (redir->stdoutfile[t] == 0) break;
    }
    /* openflag */
    farptr = MK_FP(rmod->rmodseg, RMOD_OFFSET_STDOUTAPP);
    *farptr = 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 538	Rev 543
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 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	`if (*rmodsig != 0x2019) {`	66	`if (*rmodsig != 0x2019) {`
67	`msg[22] = '1';`	67	`msg[22] = '1';`
68	`outputnl(msg);`	68	`outputnl(msg);`
69	`printf("rmodseg = %04X ; rmodsig = %04X\r\n", rmodseg, rmodsig);`	69	`printf("rmodseg = %04X ; rmodsig = %04X\r\n", rmodseg, rmodsig);`
70	`return(1);`	70	`return(1);`
71	`}`	71	`}`
72	`/* check last BUFFER byte */`	72	`/* check last BUFFER byte */`
73	`if (BUFFER[sizeof(BUFFER) - 1] != 0xC7) {`	73	`if (BUFFER[sizeof(BUFFER) - 1] != 0xC7) {`
74	`msg[22] = '2';`	74	`msg[22] = '2';`
75	`outputnl(msg);`	75	`outputnl(msg);`
76	`return(2);`	76	`return(2);`
77	`}`	77	`}`
78	`/* check last cmdlinebuf byte */`	78	`/* check last cmdlinebuf byte */`
79	`if (cmdlinebuf[CMDLINE_MAXLEN] != 0xC7) {`	79	`if (cmdlinebuf[CMDLINE_MAXLEN] != 0xC7) {`
80	`msg[22] = '3';`	80	`msg[22] = '3';`
81	`outputnl(msg);`	81	`outputnl(msg);`
82	`return(3);`	82	`return(3);`
83	`}`	83	`}`
84	`/* all good */`	84	`/* all good */`
85	`return(0);`	85	`return(0);`
86	`}`	86	`}`
87		87
88		88
89	`/* parses command line the hard way (directly from PSP) */`	89	`/* parses command line the hard way (directly from PSP) */`
90	`static void parse_argv(struct config *cfg) {`	90	`static void parse_argv(struct config *cfg) {`
91	`const unsigned char cmdlinelen = (void )0x80;`	91	`const unsigned char cmdlinelen = (void )0x80;`
92	`char cmdline = (void )0x81;`	92	`char cmdline = (void )0x81;`
93		93
94	`memset(cfg, 0, sizeof(*cfg));`	94	`memset(cfg, 0, sizeof(*cfg));`
95		95
96	`/* set a NULL terminator on cmdline */`	96	`/* set a NULL terminator on cmdline */`
97	`cmdline[*cmdlinelen] = 0;`	97	`cmdline[*cmdlinelen] = 0;`
98		98
99	`while (*cmdline != 0) {`	99	`while (*cmdline != 0) {`
100		100
101	`/* skip over any leading spaces */`	101	`/* skip over any leading spaces */`
102	`if (*cmdline == ' ') {`	102	`if (*cmdline == ' ') {`
103	`cmdline++;`	103	`cmdline++;`
104	`continue;`	104	`continue;`
105	`}`	105	`}`
106		106
107	`if (*cmdline != '/') {`	107	`if (*cmdline != '/') {`
108	`output("Invalid parameter: ");`	108	`output("Invalid parameter: ");`
109	`outputnl(cmdline);`	109	`outputnl(cmdline);`
110	`goto SKIP_TO_NEXT_ARG;`	110	`goto SKIP_TO_NEXT_ARG;`
111	`}`	111	`}`
112		112
113	`/* got a slash */`	113	`/* got a slash */`
114	`cmdline++; /* skip the slash */`	114	`cmdline++; /* skip the slash */`
115	`switch (*cmdline) {`	115	`switch (*cmdline) {`
116	`case 'c': /* /C = execute command and quit */`	116	`case 'c': /* /C = execute command and quit */`
117	`case 'C':`	117	`case 'C':`
118	`cfg->flags \|= FLAG_EXEC_AND_QUIT;`	118	`cfg->flags \|= FLAG_EXEC_AND_QUIT;`
119	`/* FALLTHRU */`	119	`/* FALLTHRU */`
120	`case 'k': /* /K = execute command and keep running */`	120	`case 'k': /* /K = execute command and keep running */`
121	`case 'K':`	121	`case 'K':`
122	`cfg->execcmd = cmdline + 1;`	122	`cfg->execcmd = cmdline + 1;`
123	`return;`	123	`return;`
124		124
125	`case 'd': /* /D = skip autoexec.bat processing */`	125	`case 'd': /* /D = skip autoexec.bat processing */`
126	`case 'D':`	126	`case 'D':`
127	`cfg->flags \|= FLAG_SKIP_AUTOEXEC;`	127	`cfg->flags \|= FLAG_SKIP_AUTOEXEC;`
128	`break;`	128	`break;`
129		129
130	`case 'e': /* preset the initial size of the environment block */`	130	`case 'e': /* preset the initial size of the environment block */`
131	`case 'E':`	131	`case 'E':`
132	`cmdline++;`	132	`cmdline++;`
133	`if (cmdline == ':') cmdline++; / could be /E:size */`	133	`if (cmdline == ':') cmdline++; / could be /E:size */`
134	`atous(&(cfg->envsiz), cmdline);`	134	`atous(&(cfg->envsiz), cmdline);`
135	`if (cfg->envsiz < 64) cfg->envsiz = 0;`	135	`if (cfg->envsiz < 64) cfg->envsiz = 0;`
136	`break;`	136	`break;`
137		137
138	`case 'p': /* permanent shell (can't exit + run autoexec.bat) */`	138	`case 'p': /* permanent shell (can't exit + run autoexec.bat) */`
139	`case 'P':`	139	`case 'P':`
140	`cfg->flags \|= FLAG_PERMANENT;`	140	`cfg->flags \|= FLAG_PERMANENT;`
141	`break;`	141	`break;`
142		142
143	`case '?':`	143	`case '?':`
144	`outputnl("Starts the SvarCOM command interpreter");`	144	`outputnl("Starts the SvarCOM command interpreter");`
145	`outputnl("");`	145	`outputnl("");`
146	`outputnl("COMMAND /E:nnn [/[C\|K] [/P] [/D] command]");`	146	`outputnl("COMMAND /E:nnn [/[C\|K] [/P] [/D] command]");`
147	`outputnl("");`	147	`outputnl("");`
148	`outputnl("/D Skip AUTOEXEC.BAT processing (makes sense only with /P)");`	148	`outputnl("/D Skip AUTOEXEC.BAT processing (makes sense only with /P)");`
149	`outputnl("/E:nnn Sets the environment size to nnn bytes");`	149	`outputnl("/E:nnn Sets the environment size to nnn bytes");`
150	`outputnl("/P Makes the new command interpreter permanent and run AUTOEXEC.BAT");`	150	`outputnl("/P Makes the new command interpreter permanent and run AUTOEXEC.BAT");`
151	`outputnl("/C Executes the specified command and returns");`	151	`outputnl("/C Executes the specified command and returns");`
152	`outputnl("/K Executes the specified command and continues running");`	152	`outputnl("/K Executes the specified command and continues running");`
153	`exit(1);`	153	`exit(1);`
154	`break;`	154	`break;`
155		155
156	`default:`	156	`default:`
157	`output("Invalid switch: /");`	157	`output("Invalid switch: /");`
158	`outputnl(cmdline);`	158	`outputnl(cmdline);`
159	`break;`	159	`break;`
160	`}`	160	`}`
161		161
162	`/* move to next argument or quit processing if end of cmdline */`	162	`/* move to next argument or quit processing if end of cmdline */`
163	`SKIP_TO_NEXT_ARG:`	163	`SKIP_TO_NEXT_ARG:`
164	`while ((cmdline != 0) && (cmdline != ' ') && (*cmdline != '/')) cmdline++;`	164	`while ((cmdline != 0) && (cmdline != ' ') && (*cmdline != '/')) cmdline++;`
165	`}`	165	`}`
166	`}`	166	`}`
167		167
168		168
169	`/* builds the prompt string and displays it. buff is filled with a zero-terminated copy of the prompt. */`	169	`/* builds the prompt string and displays it. buff is filled with a zero-terminated copy of the prompt. */`
170	`static void build_and_display_prompt(char *buff, unsigned short envseg) {`	170	`static void build_and_display_prompt(char *buff, unsigned short envseg) {`
171	`char *s = buff;`	171	`char *s = buff;`
172	`/* locate the prompt variable or use the default pattern */`	172	`/* locate the prompt variable or use the default pattern */`
173	`const char far *fmt = env_lookup_val(envseg, "PROMPT");`	173	`const char far *fmt = env_lookup_val(envseg, "PROMPT");`
174	`if ((fmt == NULL) \|\| (fmt == 0)) fmt = "$p$g"; / fallback to default if empty */`	174	`if ((fmt == NULL) \|\| (fmt == 0)) fmt = "$p$g"; / fallback to default if empty */`
175	`/* build the prompt string based on pattern */`	175	`/* build the prompt string based on pattern */`
176	`for (; *fmt != 0; fmt++) {`	176	`for (; *fmt != 0; fmt++) {`
177	`if (*fmt != '$') {`	177	`if (*fmt != '$') {`
178	`s = fmt;`	178	`s = fmt;`
179	`s++;`	179	`s++;`
180	`continue;`	180	`continue;`
181	`}`	181	`}`
182	`/* escape code ($P, etc) */`	182	`/* escape code ($P, etc) */`
183	`fmt++;`	183	`fmt++;`
184	`switch (*fmt) {`	184	`switch (*fmt) {`
185	`case 'Q': /* $Q = = (equal sign) */`	185	`case 'Q': /* $Q = = (equal sign) */`
186	`case 'q':`	186	`case 'q':`
187	`*s = '=';`	187	`*s = '=';`
188	`s++;`	188	`s++;`
189	`break;`	189	`break;`
190	`case '$': /* $$ = $ (dollar sign) */`	190	`case '$': /* $$ = $ (dollar sign) */`
191	`*s = '$';`	191	`*s = '$';`
192	`s++;`	192	`s++;`
193	`break;`	193	`break;`
194	`case 'T': /* $t = current time */`	194	`case 'T': /* $t = current time */`
195	`case 't':`	195	`case 't':`
196	`s += sprintf(s, "00:00"); /* TODO */`	196	`s += sprintf(s, "00:00"); /* TODO */`
197	`break;`	197	`break;`
198	`case 'D': /* $D = current date */`	198	`case 'D': /* $D = current date */`
199	`case 'd':`	199	`case 'd':`
200	`s += sprintf(s, "1985-07-29"); /* TODO */`	200	`s += sprintf(s, "1985-07-29"); /* TODO */`
201	`break;`	201	`break;`
202	`case 'P': /* $P = current drive and path */`	202	`case 'P': /* $P = current drive and path */`
203	`case 'p':`	203	`case 'p':`
204	`_asm {`	204	`_asm {`
205	`mov ah, 0x19 /* DOS 1+ - GET CURRENT DRIVE */`	205	`mov ah, 0x19 /* DOS 1+ - GET CURRENT DRIVE */`
206	`int 0x21`	206	`int 0x21`
207	`mov bx, s`	207	`mov bx, s`
208	`mov [bx], al /* AL = drive (00 = A:, 01 = B:, etc */`	208	`mov [bx], al /* AL = drive (00 = A:, 01 = B:, etc */`
209	`}`	209	`}`
210	`*s += 'A';`	210	`*s += 'A';`
211	`s++;`	211	`s++;`
212	`*s = ':';`	212	`*s = ':';`
213	`s++;`	213	`s++;`
214	`*s = '\\';`	214	`*s = '\\';`
215	`s++;`	215	`s++;`
216	`_asm {`	216	`_asm {`
217	`mov ah, 0x47 /* DOS 2+ - CWD - GET CURRENT DIRECTORY */`	217	`mov ah, 0x47 /* DOS 2+ - CWD - GET CURRENT DIRECTORY */`
218	`xor dl,dl /* DL = drive number (00h = default, 01h = A:, etc) */`	218	`xor dl,dl /* DL = drive number (00h = default, 01h = A:, etc) */`
219	`mov si, s /* DS:SI -> 64-byte buffer for ASCIZ pathname */`	219	`mov si, s /* DS:SI -> 64-byte buffer for ASCIZ pathname */`
220	`int 0x21`	220	`int 0x21`
221	`jc DONE /* leave path empty on error */`	221	`jc DONE /* leave path empty on error */`
222	`/* move s ptr forward to end (0-termintor) of pathname */`	222	`/* move s ptr forward to end (0-termintor) of pathname */`
223	`NEXTBYTE:`	223	`NEXTBYTE:`
224	`mov si, s`	224	`mov si, s`
225	`cmp byte ptr [si], 0`	225	`cmp byte ptr [si], 0`
226	`je DONE`	226	`je DONE`
227	`inc s`	227	`inc s`
228	`jmp NEXTBYTE`	228	`jmp NEXTBYTE`
229	`DONE:`	229	`DONE:`
230	`}`	230	`}`
231	`break;`	231	`break;`
232	`case 'V': /* $V = DOS version number */`	232	`case 'V': /* $V = DOS version number */`
233	`case 'v':`	233	`case 'v':`
234	`s += sprintf(s, "VER"); /* TODO */`	234	`s += sprintf(s, "VER"); /* TODO */`
235	`break;`	235	`break;`
236	`case 'N': /* $N = current drive */`	236	`case 'N': /* $N = current drive */`
237	`case 'n':`	237	`case 'n':`
238	`_asm {`	238	`_asm {`
239	`mov ah, 0x19 /* DOS 1+ - GET CURRENT DRIVE */`	239	`mov ah, 0x19 /* DOS 1+ - GET CURRENT DRIVE */`
240	`int 0x21`	240	`int 0x21`
241	`mov bx, s`	241	`mov bx, s`
242	`mov [bx], al /* AL = drive (00 = A:, 01 = B:, etc */`	242	`mov [bx], al /* AL = drive (00 = A:, 01 = B:, etc */`
243	`}`	243	`}`
244	`*s += 'A';`	244	`*s += 'A';`
245	`s++;`	245	`s++;`
246	`break;`	246	`break;`
247	`case 'G': /* $G = > (greater-than sign) */`	247	`case 'G': /* $G = > (greater-than sign) */`
248	`case 'g':`	248	`case 'g':`
249	`*s = '>';`	249	`*s = '>';`
250	`s++;`	250	`s++;`
251	`break;`	251	`break;`
252	`case 'L': /* $L = < (less-than sign) */`	252	`case 'L': /* $L = < (less-than sign) */`
253	`case 'l':`	253	`case 'l':`
254	`*s = '<';`	254	`*s = '<';`
255	`s++;`	255	`s++;`
256	`break;`	256	`break;`
257	`case 'B': /* $B = \| (pipe) */`	257	`case 'B': /* $B = \| (pipe) */`
258	`case 'b':`	258	`case 'b':`
259	`*s = '\|';`	259	`*s = '\|';`
260	`s++;`	260	`s++;`
261	`break;`	261	`break;`
262	`case 'H': /* $H = backspace (erases previous character) */`	262	`case 'H': /* $H = backspace (erases previous character) */`
263	`case 'h':`	263	`case 'h':`
264	`*s = '\b';`	264	`*s = '\b';`
265	`s++;`	265	`s++;`
266	`break;`	266	`break;`
267	`case 'E': /* $E = Escape code (ASCII 27) */`	267	`case 'E': /* $E = Escape code (ASCII 27) */`
268	`case 'e':`	268	`case 'e':`
269	`*s = 27;`	269	`*s = 27;`
270	`s++;`	270	`s++;`
271	`break;`	271	`break;`
272	`case '_': /* $_ = CR+LF */`	272	`case '_': /* $_ = CR+LF */`
273	`*s = '\r';`	273	`*s = '\r';`
274	`s++;`	274	`s++;`
275	`*s = '\n';`	275	`*s = '\n';`
276	`s++;`	276	`s++;`
277	`break;`	277	`break;`
278	`}`	278	`}`
279	`}`	279	`}`
280	`*s = 0;`	280	`*s = 0;`
281	`output(buff);`	281	`output(buff);`
282	`}`	282	`}`
283		283
284		284
285	`/* tries locating executable fname in path and fill res with result. returns 0 on success,`	285	`/* tries locating executable fname in path and fill res with result. returns 0 on success,`
286	`* -1 on failed match and -2 on failed match + "don't even try with other paths"`	286	`* -1 on failed match and -2 on failed match + "don't even try with other paths"`
287	`* extptr contains a ptr to the extension in fname (NULL if not found) */`	287	`* extptr contains a ptr to the extension in fname (NULL if not found) */`
288	`static int lookup_cmd(char res, const char fname, const char path, const char *extptr) {`	288	`static int lookup_cmd(char res, const char fname, const char path, const char *extptr) {`
289	`unsigned short lastbslash = 0;`	289	`unsigned short lastbslash = 0;`
290	`unsigned short i, len;`	290	`unsigned short i, len;`
291	`unsigned char explicitpath = 0;`	291	`unsigned char explicitpath = 0;`
292		292
293	`/* does the original fname has an explicit path prefix or explicit ext? */`	293	`/* does the original fname has an explicit path prefix or explicit ext? */`
294	`*extptr = NULL;`	294	`*extptr = NULL;`
295	`for (i = 0; fname[i] != 0; i++) {`	295	`for (i = 0; fname[i] != 0; i++) {`
296	`switch (fname[i]) {`	296	`switch (fname[i]) {`
297	`case ':':`	297	`case ':':`
298	`case '\\':`	298	`case '\\':`
299	`explicitpath = 1;`	299	`explicitpath = 1;`
300	`extptr = NULL; / extension is the last dot AFTER all path delimiters */`	300	`extptr = NULL; / extension is the last dot AFTER all path delimiters */`
301	`break;`	301	`break;`
302	`case '.':`	302	`case '.':`
303	`*extptr = fname + i + 1;`	303	`*extptr = fname + i + 1;`
304	`break;`	304	`break;`
305	`}`	305	`}`
306	`}`	306	`}`
307		307
308	`/* normalize filename */`	308	`/* normalize filename */`
309	`if (file_truename(fname, res) != 0) return(-2);`	309	`if (file_truename(fname, res) != 0) return(-2);`
310		310
311	`/* printf("truename: %s\r\n", res); */`	311	`/* printf("truename: %s\r\n", res); */`
312		312
313	`/* figure out where the command starts and if it has an explicit extension */`	313	`/* figure out where the command starts and if it has an explicit extension */`
314	`for (len = 0; res[len] != 0; len++) {`	314	`for (len = 0; res[len] != 0; len++) {`
315	`switch (res[len]) {`	315	`switch (res[len]) {`
316	`case '?': /* abort on any wildcard character */`	316	`case '?': /* abort on any wildcard character */`
317	`case '*':`	317	`case '*':`
318	`return(-2);`	318	`return(-2);`
319	`case '\\':`	319	`case '\\':`
320	`lastbslash = len;`	320	`lastbslash = len;`
321	`break;`	321	`break;`
322	`}`	322	`}`
323	`}`	323	`}`
324		324
325	`/* printf("lastbslash=%u\r\n", lastbslash); */`	325	`/* printf("lastbslash=%u\r\n", lastbslash); */`
326		326
327	`/* if no path prefix was found in fname (no colon or backslash) AND we have`	327	`/* if no path prefix was found in fname (no colon or backslash) AND we have`
328	`* a path arg, then assemble path+filename */`	328	`* a path arg, then assemble path+filename */`
329	`if ((!explicitpath) && (path != NULL) && (path[0] != 0)) {`	329	`if ((!explicitpath) && (path != NULL) && (path[0] != 0)) {`
330	`i = strlen(path);`	330	`i = strlen(path);`
331	`if (path[i - 1] != '\\') i++; /* add a byte for inserting a bkslash after path */`	331	`if (path[i - 1] != '\\') i++; /* add a byte for inserting a bkslash after path */`
332	`/* move the filename at the place where path will end */`	332	`/* move the filename at the place where path will end */`
333	`memmove(res + i, res + lastbslash + 1, len - lastbslash);`	333	`memmove(res + i, res + lastbslash + 1, len - lastbslash);`
334	`/* copy path in front of the filename and make sure there is a bkslash sep */`	334	`/* copy path in front of the filename and make sure there is a bkslash sep */`
335	`memmove(res, path, i);`	335	`memmove(res, path, i);`
336	`res[i - 1] = '\\';`	336	`res[i - 1] = '\\';`
337	`}`	337	`}`
338		338
339	`/* if no extension was initially provided, try matching COM, EXE, BAT */`	339	`/* if no extension was initially provided, try matching COM, EXE, BAT */`
340	`if (*extptr == NULL) {`	340	`if (*extptr == NULL) {`
341	`const char *ext[] = {".COM", ".EXE", ".BAT", NULL};`	341	`const char *ext[] = {".COM", ".EXE", ".BAT", NULL};`
342	`len = strlen(res);`	342	`len = strlen(res);`
343	`for (i = 0; ext[i] != NULL; i++) {`	343	`for (i = 0; ext[i] != NULL; i++) {`
344	`strcpy(res + len, ext[i]);`	344	`strcpy(res + len, ext[i]);`
345	`/* printf("? '%s'\r\n", res); */`	345	`/* printf("? '%s'\r\n", res); */`
346	`*extptr = ext[i] + 1;`	346	`*extptr = ext[i] + 1;`
347	`if (file_getattr(res) >= 0) return(0);`	347	`if (file_getattr(res) >= 0) return(0);`
348	`}`	348	`}`
349	`} else { /* try finding it as-is */`	349	`} else { /* try finding it as-is */`
350	`/* printf("? '%s'\r\n", res); */`	350	`/* printf("? '%s'\r\n", res); */`
351	`if (file_getattr(res) >= 0) return(0);`	351	`if (file_getattr(res) >= 0) return(0);`
352	`}`	352	`}`
353		353
354	`/* not found */`	354	`/* not found */`
355	`if (explicitpath) return(-2); /* don't bother trying other paths, the caller had its own path preset anyway */`	355	`if (explicitpath) return(-2); /* don't bother trying other paths, the caller had its own path preset anyway */`
356	`return(-1);`	356	`return(-1);`
357	`}`	357	`}`
358		358
359		359
360	`static void run_as_external(char buff, const char cmdline, unsigned short envseg, struct rmod_props far rmod, struct redir_data redir) {`	360	`static void run_as_external(char buff, const char cmdline, unsigned short envseg, struct rmod_props far rmod, struct redir_data redir) {`
361	`char *cmdfile = buff + 512;`	361	`char *cmdfile = buff + 512;`
362	`const char far *pathptr;`	362	`const char far *pathptr;`
363	`int lookup;`	363	`int lookup;`
364	`unsigned short i;`	364	`unsigned short i;`
365	`const char *ext;`	365	`const char *ext;`
366	`char *cmd = buff + 1024;`	366	`char *cmd = buff + 1024;`
367	`const char *cmdtail;`	367	`const char *cmdtail;`
368	`char far *rmod_execprog = MK_FP(rmod->rmodseg, RMOD_OFFSET_EXECPROG);`	368	`char far *rmod_execprog = MK_FP(rmod->rmodseg, RMOD_OFFSET_EXECPROG);`
369	`char far *rmod_cmdtail = MK_FP(rmod->rmodseg, 0x81);`	369	`char far *rmod_cmdtail = MK_FP(rmod->rmodseg, 0x81);`
370	`_Packed struct {`	370	`_Packed struct {`
371	`unsigned short envseg;`	371	`unsigned short envseg;`
372	`unsigned long cmdtail;`	372	`unsigned long cmdtail;`
373	`unsigned long fcb1;`	373	`unsigned long fcb1;`
374	`unsigned long fcb2;`	374	`unsigned long fcb2;`
375	`} far *ExecParam = MK_FP(rmod->rmodseg, RMOD_OFFSET_EXECPARAM);`	375	`} far *ExecParam = MK_FP(rmod->rmodseg, RMOD_OFFSET_EXECPARAM);`
376		376
377	`/* find cmd and cmdtail */`	377	`/* find cmd and cmdtail */`
378	`i = 0;`	378	`i = 0;`
379	`cmdtail = cmdline;`	379	`cmdtail = cmdline;`
380	`while (cmdtail == ' ') cmdtail++; / skip any leading spaces */`	380	`while (cmdtail == ' ') cmdtail++; / skip any leading spaces */`
381	`while ((cmdtail != ' ') && (cmdtail != '/') && (cmdtail != '+') && (cmdtail != 0)) {`	381	`while ((cmdtail != ' ') && (cmdtail != '/') && (cmdtail != '+') && (cmdtail != 0)) {`
382	`cmd[i++] = *cmdtail;`	382	`cmd[i++] = *cmdtail;`
383	`cmdtail++;`	383	`cmdtail++;`
384	`}`	384	`}`
385	`cmd[i] = 0;`	385	`cmd[i] = 0;`
386		386
387	`/* is this a command in curdir? */`	387	`/* is this a command in curdir? */`
388	`lookup = lookup_cmd(cmdfile, cmd, NULL, &ext);`	388	`lookup = lookup_cmd(cmdfile, cmd, NULL, &ext);`
389	`if (lookup == 0) {`	389	`if (lookup == 0) {`
390	`/* printf("FOUND LOCAL EXEC FILE: '%s'\r\n", cmdfile); */`	390	`/* printf("FOUND LOCAL EXEC FILE: '%s'\r\n", cmdfile); */`
391	`goto RUNCMDFILE;`	391	`goto RUNCMDFILE;`
392	`} else if (lookup == -2) {`	392	`} else if (lookup == -2) {`
393	`/* puts("NOT FOUND"); */`	393	`/* puts("NOT FOUND"); */`
394	`return;`	394	`return;`
395	`}`	395	`}`
396		396
397	`/* try matching something in PATH */`	397	`/* try matching something in PATH */`
398	`pathptr = env_lookup_val(envseg, "PATH");`	398	`pathptr = env_lookup_val(envseg, "PATH");`
399	`if (pathptr == NULL) return;`	399	`if (pathptr == NULL) return;`
400		400
401	`/* try each path in %PATH% */`	401	`/* try each path in %PATH% */`
402	`for (;;) {`	402	`for (;;) {`
403	`for (i = 0;; i++) {`	403	`for (i = 0;; i++) {`
404	`buff[i] = *pathptr;`	404	`buff[i] = *pathptr;`
405	`if ((buff[i] == 0) \|\| (buff[i] == ';')) break;`	405	`if ((buff[i] == 0) \|\| (buff[i] == ';')) break;`
406	`pathptr++;`	406	`pathptr++;`
407	`}`	407	`}`
408	`buff[i] = 0;`	408	`buff[i] = 0;`
409	`lookup = lookup_cmd(cmdfile, cmd, buff, &ext);`	409	`lookup = lookup_cmd(cmdfile, cmd, buff, &ext);`
410	`if (lookup == 0) break;`	410	`if (lookup == 0) break;`
411	`if (lookup == -2) return;`	411	`if (lookup == -2) return;`
412	`if (*pathptr == ';') {`	412	`if (*pathptr == ';') {`
413	`pathptr++;`	413	`pathptr++;`
414	`} else {`	414	`} else {`
415	`return;`	415	`return;`
416	`}`	416	`}`
417	`}`	417	`}`
418		418
419	`RUNCMDFILE:`	419	`RUNCMDFILE:`
420		420
421	`/* special handling of batch files */`	421	`/* special handling of batch files */`
422	`if ((ext != NULL) && (imatch(ext, "bat"))) {`	422	`if ((ext != NULL) && (imatch(ext, "bat"))) {`
423	`/* copy truename of the bat file to rmod buff */`	423	`/* copy truename of the bat file to rmod buff */`
424	`for (i = 0; cmdfile[i] != 0; i++) rmod->batfile[i] = cmdfile[i];`	424	`for (i = 0; cmdfile[i] != 0; i++) rmod->batfile[i] = cmdfile[i];`
425	`rmod->batfile[i] = 0;`	425	`rmod->batfile[i] = 0;`
426		426
427	`/* explode args of the bat file and store them in rmod buff */`	427	`/* explode args of the bat file and store them in rmod buff */`
428	`cmd_explode(buff, cmdline, NULL);`	428	`cmd_explode(buff, cmdline, NULL);`
429	`_fmemcpy(rmod->batargv, buff, sizeof(rmod->batargv));`	429	`_fmemcpy(rmod->batargv, buff, sizeof(rmod->batargv));`
430		430
431	`/* reset the 'next line to execute' counter */`	431	`/* reset the 'next line to execute' counter */`
432	`rmod->batnextline = 0;`	432	`rmod->batnextline = 0;`
433	`/* remember the echo flag (in case bat file disables echo) */`	433	`/* remember the echo flag (in case bat file disables echo) */`
434	`rmod->flags &= ~FLAG_ECHO_BEFORE_BAT;`	434	`rmod->flags &= ~FLAG_ECHO_BEFORE_BAT;`
435	`if (rmod->flags & FLAG_ECHOFLAG) rmod->flags \|= FLAG_ECHO_BEFORE_BAT;`	435	`if (rmod->flags & FLAG_ECHOFLAG) rmod->flags \|= FLAG_ECHO_BEFORE_BAT;`
436	`return;`	436	`return;`
437	`}`	437	`}`
438		438
439	`/* copy full filename to execute, along with redirected files (if any) */`	439	`/* copy full filename to execute, along with redirected files (if any) */`
440	`for (i = 0; cmdfile[i] != 0; i++) rmod_execprog[i] = cmdfile[i];`	440	`for (i = 0; cmdfile[i] != 0; i++) rmod_execprog[i] = cmdfile[i];`
441	`rmod_execprog[i++] = 0;`	441	`rmod_execprog[i++] = 0;`
442	`if (redir->stdinfile) {`	442	`if (redir->stdinfile) {`
443	`unsigned short far *farptr = MK_FP(rmod->rmodseg, RMOD_OFFSET_STDINFILE);`	443	`unsigned short far *farptr = MK_FP(rmod->rmodseg, RMOD_OFFSET_STDINFILE);`
444	`unsigned short t;`	444	`unsigned short t;`
445	`*farptr = i;`	445	`*farptr = i;`
446	`for (t = 0;; t++) {`	446	`for (t = 0;; t++) {`
447	`rmod_execprog[i++] = redir->stdinfile[t];`	447	`rmod_execprog[i++] = redir->stdinfile[t];`
448	`if (redir->stdinfile[t] == 0) break;`	448	`if (redir->stdinfile[t] == 0) break;`
449	`}`	449	`}`
450	`}`	450	`}`
451	`if (redir->stdoutfile) {`	451	`if (redir->stdoutfile) {`
452	`unsigned short far *farptr = MK_FP(rmod->rmodseg, RMOD_OFFSET_STDOUTFILE);`	452	`unsigned short far *farptr = MK_FP(rmod->rmodseg, RMOD_OFFSET_STDOUTFILE);`
453	`unsigned short t;`	453	`unsigned short t;`
454	`*farptr = i;`	454	`*farptr = i;`
455	`for (t = 0;; t++) {`	455	`for (t = 0;; t++) {`
456	`rmod_execprog[i++] = redir->stdoutfile[t];`	456	`rmod_execprog[i++] = redir->stdoutfile[t];`
457	`if (redir->stdoutfile[t] == 0) break;`	457	`if (redir->stdoutfile[t] == 0) break;`
458	`}`	458	`}`
459	`/* openflag */`	459	`/* openflag */`
460	`farptr = MK_FP(rmod->rmodseg, RMOD_OFFSET_STDOUTAPP);`	460	`farptr = MK_FP(rmod->rmodseg, RMOD_OFFSET_STDOUTAPP);`
461	`*farptr = redir->stdout_openflag;`	461	`*farptr = redir->stdout_openflag;`
462	`}`	462	`}`
463		463
464	`/* copy cmdtail to rmod's PSP and compute its len */`	464	`/* copy cmdtail to rmod's PSP and compute its len */`
465	`for (i = 0; cmdtail[i] != 0; i++) rmod_cmdtail[i] = cmdtail[i];`	465	`for (i = 0; cmdtail[i] != 0; i++) rmod_cmdtail[i] = cmdtail[i];`
466	`rmod_cmdtail[i] = '\r';`	466	`rmod_cmdtail[i] = '\r';`
467	`rmod_cmdtail[-1] = i;`	467	`rmod_cmdtail[-1] = i;`
468		468
469	`/* set up rmod to execute the command */`	469	`/* set up rmod to execute the command */`
470		470
471	`ExecParam->envseg = envseg;`	471	`ExecParam->envseg = envseg;`
472	`ExecParam->cmdtail = (unsigned long)MK_FP(rmod->rmodseg, 0x80); /* farptr, must be in PSP format (lenbyte args \r) */`	472	`ExecParam->cmdtail = (unsigned long)MK_FP(rmod->rmodseg, 0x80); /* farptr, must be in PSP format (lenbyte args \r) */`
473	`ExecParam->fcb1 = 0; /* TODO farptr */`	473	`ExecParam->fcb1 = 0; /* TODO farptr */`
474	`ExecParam->fcb2 = 0; /* TODO farptr */`	474	`ExecParam->fcb2 = 0; /* TODO farptr */`
475	`exit(0); /* let rmod do the job now */`	475	`exit(0); /* let rmod do the job now */`
476	`}`	476	`}`
477		477
478		478
479	`static void set_comspec_to_self(unsigned short envseg) {`	479	`static void set_comspec_to_self(unsigned short envseg) {`
480	`unsigned short psp_envseg = (void )(0x2c); /* pointer to my env segment field in the PSP */`	480	`unsigned short psp_envseg = (void )(0x2c); /* pointer to my env segment field in the PSP */`
481	`char far myenv = MK_FP(psp_envseg, 0);`	481	`char far myenv = MK_FP(psp_envseg, 0);`
482	`unsigned short varcount;`	482	`unsigned short varcount;`
483	`char buff[256] = "COMSPEC=";`	483	`char buff[256] = "COMSPEC=";`
484	`char *buffptr = buff + 8;`	484	`char *buffptr = buff + 8;`
485	`/* who am i? look into my own environment, at the end of it should be my EXEPATH string */`	485	`/* who am i? look into my own environment, at the end of it should be my EXEPATH string */`
486	`while (*myenv != 0) {`	486	`while (*myenv != 0) {`
487	`/* consume a NULL-terminated string */`	487	`/* consume a NULL-terminated string */`
488	`while (*myenv != 0) myenv++;`	488	`while (*myenv != 0) myenv++;`
489	`/* move to next string */`	489	`/* move to next string */`
490	`myenv++;`	490	`myenv++;`
491	`}`	491	`}`
492	`/* get next word, if 1 then EXEPATH follows */`	492	`/* get next word, if 1 then EXEPATH follows */`
493	`myenv++;`	493	`myenv++;`
494	`varcount = *myenv;`	494	`varcount = *myenv;`
495	`myenv++;`	495	`myenv++;`
496	`varcount \|= (*myenv << 8);`	496	`varcount \|= (*myenv << 8);`
497	`myenv++;`	497	`myenv++;`
498	`if (varcount != 1) return; /* NO EXEPATH FOUND */`	498	`if (varcount != 1) return; /* NO EXEPATH FOUND */`
499	`while (*myenv != 0) {`	499	`while (*myenv != 0) {`
500	`buffptr = myenv;`	500	`buffptr = myenv;`

Subversion Repositories SvarDOS

(root)/svarcom/trunk/command.c – Rev 538 → 543