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
        }
        while (*s != 0) s++; /* move ptr forward to end of pathname */
        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 fille res with result. returns 0 on success,
 * -1 on failed match and -2 on failed match + "don't even try with other paths"
 * format is filled the offset where extension starts in fname (-1 if not found) */
int lookup_cmd(char *res, const char *fname, const char *path, const char **extptr) {
  unsigned short lastbslash = 0xffff;
  unsigned short i, len;
  unsigned char explicitpath = 0;
 
  /* does the original fname had 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 in fname (':' or backslash), then assemble path+filename */
  if (!explicitpath) {
    if (path != NULL) {
      i = strlen(path);
    } else {
      i = 0;
    }
    if ((i != 0) && (path[i - 1] != '\\')) i++; /* add a byte for inserting a bkslash after path */
    memmove(res + i, res + lastbslash + 1, len - lastbslash);
    if (i != 0) {
      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) {
  char *cmdfile = buff + 512;
  const char far *pathptr;
  int lookup;
  unsigned short i;
  const char *ext;
  char *cmd = buff + 256;
  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;
    /* copy args of the bat file to rmod buff */
    for (i = 0; cmdtail[i] != 0; i++) rmod->batargs[i] = cmdtail[i];
    /* 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 */
  for (i = 0; cmdfile[i] != 0; i++) rmod_execprog[i] = cmdfile[i];
  rmod_execprog[i] = 0;
 
  /* 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;
 
  /* 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 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 DONE
    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 CLOSEANDQUIT
 
    /* 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 CLOSEANDQUIT
    mov blen, al
 
    CLOSEANDQUIT:
    /* close file (handle in bx) */
    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); */
 
  /* 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);
}
 
 
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;
 
  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);
 
    /* 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(cmdline, 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;
      }
      /* 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) */
    if (redir_parsecmd(cmdline, BUFFER) != 0) {
      outputnl("");
      continue;
    }
 
    /* try matching (and executing) an internal command */
    if (cmd_process(rmod, *rmod_envseg, cmdline, BUFFER, sizeof(BUFFER)) >= -1) {
      /* internal command executed */
      redir_revert(); /* revert stdout (in case it was redirected) */
      continue;
    }
 
    /* if here, then this was not an internal command */
    run_as_external(BUFFER, cmdline, *rmod_envseg, rmod);
    /* perhaps this is a newly launched BAT file */
    if ((rmod->batfile[0] != 0) && (rmod->batnextline == 0)) goto SKIP_NEWLINE;
 
    /* revert stdout (so the err msg is not redirected) */
    redir_revert();
 
    /* 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");
 
  } while ((rmod->flags & FLAG_EXEC_AND_QUIT) == 0);
 
  sayonara(rmod);
  return(0);
}
 

Rev 494	Rev 500
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(void) {`	55	`static void memguard_set(char *cmdlinebuf) {`
56	`BUFFER[sizeof(BUFFER) - 1] = 0xC7;`	56	`BUFFER[sizeof(BUFFER) - 1] = 0xC7;`
57	`BUFFER[sizeof(BUFFER) - (CMDLINE_MAXLEN + 3)] = 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) {`	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 (could be overwritten by cmdline) */`	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 that cmdline BUFFER's end hasn't been touched by something else */`	78	`/* check last cmdlinebuf byte */`
79	`if (BUFFER[sizeof(BUFFER) - (CMDLINE_MAXLEN + 3)] != 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	`}`	221	`}`
222	`while (s != 0) s++; / move ptr forward to end of pathname */`	222	`while (s != 0) s++; / move ptr forward to end of pathname */`
223	`break;`	223	`break;`
224	`case 'V': /* $V = DOS version number */`	224	`case 'V': /* $V = DOS version number */`
225	`case 'v':`	225	`case 'v':`
226	`s += sprintf(s, "VER"); /* TODO */`	226	`s += sprintf(s, "VER"); /* TODO */`
227	`break;`	227	`break;`
228	`case 'N': /* $N = current drive */`	228	`case 'N': /* $N = current drive */`
229	`case 'n':`	229	`case 'n':`
230	`_asm {`	230	`_asm {`
231	`mov ah, 0x19 /* DOS 1+ - GET CURRENT DRIVE */`	231	`mov ah, 0x19 /* DOS 1+ - GET CURRENT DRIVE */`
232	`int 0x21`	232	`int 0x21`
233	`mov bx, s`	233	`mov bx, s`
234	`mov [bx], al /* AL = drive (00 = A:, 01 = B:, etc */`	234	`mov [bx], al /* AL = drive (00 = A:, 01 = B:, etc */`
235	`}`	235	`}`
236	`*s += 'A';`	236	`*s += 'A';`
237	`s++;`	237	`s++;`
238	`break;`	238	`break;`
239	`case 'G': /* $G = > (greater-than sign) */`	239	`case 'G': /* $G = > (greater-than sign) */`
240	`case 'g':`	240	`case 'g':`
241	`*s = '>';`	241	`*s = '>';`
242	`s++;`	242	`s++;`
243	`break;`	243	`break;`
244	`case 'L': /* $L = < (less-than sign) */`	244	`case 'L': /* $L = < (less-than sign) */`
245	`case 'l':`	245	`case 'l':`
246	`*s = '<';`	246	`*s = '<';`
247	`s++;`	247	`s++;`
248	`break;`	248	`break;`
249	`case 'B': /* $B = \| (pipe) */`	249	`case 'B': /* $B = \| (pipe) */`
250	`case 'b':`	250	`case 'b':`
251	`*s = '\|';`	251	`*s = '\|';`
252	`s++;`	252	`s++;`
253	`break;`	253	`break;`
254	`case 'H': /* $H = backspace (erases previous character) */`	254	`case 'H': /* $H = backspace (erases previous character) */`
255	`case 'h':`	255	`case 'h':`
256	`*s = '\b';`	256	`*s = '\b';`
257	`s++;`	257	`s++;`
258	`break;`	258	`break;`
259	`case 'E': /* $E = Escape code (ASCII 27) */`	259	`case 'E': /* $E = Escape code (ASCII 27) */`
260	`case 'e':`	260	`case 'e':`
261	`*s = 27;`	261	`*s = 27;`
262	`s++;`	262	`s++;`
263	`break;`	263	`break;`
264	`case '_': /* $_ = CR+LF */`	264	`case '_': /* $_ = CR+LF */`
265	`*s = '\r';`	265	`*s = '\r';`
266	`s++;`	266	`s++;`
267	`*s = '\n';`	267	`*s = '\n';`
268	`s++;`	268	`s++;`
269	`break;`	269	`break;`
270	`}`	270	`}`
271	`}`	271	`}`
272	`*s = 0;`	272	`*s = 0;`
273	`output(buff);`	273	`output(buff);`
274	`}`	274	`}`
275		275
276		276
277	`/* tries locating executable fname in path and fille res with result. returns 0 on success,`	277	`/* tries locating executable fname in path and fille res with result. returns 0 on success,`
278	`* -1 on failed match and -2 on failed match + "don't even try with other paths"`	278	`* -1 on failed match and -2 on failed match + "don't even try with other paths"`
279	`* format is filled the offset where extension starts in fname (-1 if not found) */`	279	`* format is filled the offset where extension starts in fname (-1 if not found) */`
280	`int lookup_cmd(char res, const char fname, const char path, const char *extptr) {`	280	`int lookup_cmd(char res, const char fname, const char path, const char *extptr) {`
281	`unsigned short lastbslash = 0xffff;`	281	`unsigned short lastbslash = 0xffff;`
282	`unsigned short i, len;`	282	`unsigned short i, len;`
283	`unsigned char explicitpath = 0;`	283	`unsigned char explicitpath = 0;`
284		284
285	`/* does the original fname had an explicit path prefix or explicit ext? */`	285	`/* does the original fname had an explicit path prefix or explicit ext? */`
286	`*extptr = NULL;`	286	`*extptr = NULL;`
287	`for (i = 0; fname[i] != 0; i++) {`	287	`for (i = 0; fname[i] != 0; i++) {`
288	`switch (fname[i]) {`	288	`switch (fname[i]) {`
289	`case ':':`	289	`case ':':`
290	`case '\\':`	290	`case '\\':`
291	`explicitpath = 1;`	291	`explicitpath = 1;`
292	`extptr = NULL; / extension is the last dot AFTER all path delimiters */`	292	`extptr = NULL; / extension is the last dot AFTER all path delimiters */`
293	`break;`	293	`break;`
294	`case '.':`	294	`case '.':`
295	`*extptr = fname + i + 1;`	295	`*extptr = fname + i + 1;`
296	`break;`	296	`break;`
297	`}`	297	`}`
298	`}`	298	`}`
299		299
300	`/* normalize filename */`	300	`/* normalize filename */`
301	`if (file_truename(fname, res) != 0) return(-2);`	301	`if (file_truename(fname, res) != 0) return(-2);`
302		302
303	`/* printf("truename: %s\r\n", res); */`	303	`/* printf("truename: %s\r\n", res); */`
304		304
305	`/* figure out where the command starts and if it has an explicit extension */`	305	`/* figure out where the command starts and if it has an explicit extension */`
306	`for (len = 0; res[len] != 0; len++) {`	306	`for (len = 0; res[len] != 0; len++) {`
307	`switch (res[len]) {`	307	`switch (res[len]) {`
308	`case '?': /* abort on any wildcard character */`	308	`case '?': /* abort on any wildcard character */`
309	`case '*':`	309	`case '*':`
310	`return(-2);`	310	`return(-2);`
311	`case '\\':`	311	`case '\\':`
312	`lastbslash = len;`	312	`lastbslash = len;`
313	`break;`	313	`break;`
314	`}`	314	`}`
315	`}`	315	`}`
316		316
317	`/* printf("lastbslash=%u\r\n", lastbslash); */`	317	`/* printf("lastbslash=%u\r\n", lastbslash); */`
318		318
319	`/* if no path prefix in fname (':' or backslash), then assemble path+filename */`	319	`/* if no path prefix in fname (':' or backslash), then assemble path+filename */`
320	`if (!explicitpath) {`	320	`if (!explicitpath) {`
321	`if (path != NULL) {`	321	`if (path != NULL) {`
322	`i = strlen(path);`	322	`i = strlen(path);`
323	`} else {`	323	`} else {`
324	`i = 0;`	324	`i = 0;`
325	`}`	325	`}`
326	`if ((i != 0) && (path[i - 1] != '\\')) i++; /* add a byte for inserting a bkslash after path */`	326	`if ((i != 0) && (path[i - 1] != '\\')) i++; /* add a byte for inserting a bkslash after path */`
327	`memmove(res + i, res + lastbslash + 1, len - lastbslash);`	327	`memmove(res + i, res + lastbslash + 1, len - lastbslash);`
328	`if (i != 0) {`	328	`if (i != 0) {`
329	`memmove(res, path, i);`	329	`memmove(res, path, i);`
330	`res[i - 1] = '\\';`	330	`res[i - 1] = '\\';`
331	`}`	331	`}`
332	`}`	332	`}`
333		333
334	`/* if no extension was initially provided, try matching COM, EXE, BAT */`	334	`/* if no extension was initially provided, try matching COM, EXE, BAT */`
335	`if (*extptr == NULL) {`	335	`if (*extptr == NULL) {`
336	`const char *ext[] = {".COM", ".EXE", ".BAT", NULL};`	336	`const char *ext[] = {".COM", ".EXE", ".BAT", NULL};`
337	`len = strlen(res);`	337	`len = strlen(res);`
338	`for (i = 0; ext[i] != NULL; i++) {`	338	`for (i = 0; ext[i] != NULL; i++) {`
339	`strcpy(res + len, ext[i]);`	339	`strcpy(res + len, ext[i]);`
340	`/* printf("? '%s'\r\n", res); */`	340	`/* printf("? '%s'\r\n", res); */`
341	`*extptr = ext[i] + 1;`	341	`*extptr = ext[i] + 1;`
342	`if (file_getattr(res) >= 0) return(0);`	342	`if (file_getattr(res) >= 0) return(0);`
343	`}`	343	`}`
344	`} else { /* try finding it as-is */`	344	`} else { /* try finding it as-is */`
345	`/* printf("? '%s'\r\n", res); */`	345	`/* printf("? '%s'\r\n", res); */`
346	`if (file_getattr(res) >= 0) return(0);`	346	`if (file_getattr(res) >= 0) return(0);`
347	`}`	347	`}`
348		348
349	`/* not found */`	349	`/* not found */`
350	`if (explicitpath) return(-2); /* don't bother trying other paths, the caller had its own path preset anyway */`	350	`if (explicitpath) return(-2); /* don't bother trying other paths, the caller had its own path preset anyway */`
351	`return(-1);`	351	`return(-1);`
352	`}`	352	`}`
353		353
354		354
355	`static void run_as_external(char buff, const char cmdline, unsigned short envseg, struct rmod_props far *rmod) {`	355	`static void run_as_external(char buff, const char cmdline, unsigned short envseg, struct rmod_props far *rmod) {`
356	`char *cmdfile = buff + 512;`	356	`char *cmdfile = buff + 512;`
357	`const char far *pathptr;`	357	`const char far *pathptr;`
358	`int lookup;`	358	`int lookup;`
359	`unsigned short i;`	359	`unsigned short i;`
360	`const char *ext;`	360	`const char *ext;`
361	`char *cmd = buff + 256;`	361	`char *cmd = buff + 256;`
362	`const char *cmdtail;`	362	`const char *cmdtail;`
363	`char far *rmod_execprog = MK_FP(rmod->rmodseg, RMOD_OFFSET_EXECPROG);`	363	`char far *rmod_execprog = MK_FP(rmod->rmodseg, RMOD_OFFSET_EXECPROG);`
364	`char far *rmod_cmdtail = MK_FP(rmod->rmodseg, 0x81);`	364	`char far *rmod_cmdtail = MK_FP(rmod->rmodseg, 0x81);`
365	`_Packed struct {`	365	`_Packed struct {`
366	`unsigned short envseg;`	366	`unsigned short envseg;`
367	`unsigned long cmdtail;`	367	`unsigned long cmdtail;`
368	`unsigned long fcb1;`	368	`unsigned long fcb1;`
369	`unsigned long fcb2;`	369	`unsigned long fcb2;`
370	`} far *ExecParam = MK_FP(rmod->rmodseg, RMOD_OFFSET_EXECPARAM);`	370	`} far *ExecParam = MK_FP(rmod->rmodseg, RMOD_OFFSET_EXECPARAM);`
371		371
372	`/* find cmd and cmdtail */`	372	`/* find cmd and cmdtail */`
373	`i = 0;`	373	`i = 0;`
374	`cmdtail = cmdline;`	374	`cmdtail = cmdline;`
375	`while (cmdtail == ' ') cmdtail++; / skip any leading spaces */`	375	`while (cmdtail == ' ') cmdtail++; / skip any leading spaces */`
376	`while ((cmdtail != ' ') && (cmdtail != '/') && (cmdtail != '+') && (cmdtail != 0)) {`	376	`while ((cmdtail != ' ') && (cmdtail != '/') && (cmdtail != '+') && (cmdtail != 0)) {`
377	`cmd[i++] = *cmdtail;`	377	`cmd[i++] = *cmdtail;`
378	`cmdtail++;`	378	`cmdtail++;`
379	`}`	379	`}`
380	`cmd[i] = 0;`	380	`cmd[i] = 0;`
381		381
382	`/* is this a command in curdir? */`	382	`/* is this a command in curdir? */`
383	`lookup = lookup_cmd(cmdfile, cmd, NULL, &ext);`	383	`lookup = lookup_cmd(cmdfile, cmd, NULL, &ext);`
384	`if (lookup == 0) {`	384	`if (lookup == 0) {`
385	`/* printf("FOUND LOCAL EXEC FILE: '%s'\r\n", cmdfile); */`	385	`/* printf("FOUND LOCAL EXEC FILE: '%s'\r\n", cmdfile); */`
386	`goto RUNCMDFILE;`	386	`goto RUNCMDFILE;`
387	`} else if (lookup == -2) {`	387	`} else if (lookup == -2) {`
388	`/* puts("NOT FOUND"); */`	388	`/* puts("NOT FOUND"); */`
389	`return;`	389	`return;`
390	`}`	390	`}`
391		391
392	`/* try matching something in PATH */`	392	`/* try matching something in PATH */`
393	`pathptr = env_lookup_val(envseg, "PATH");`	393	`pathptr = env_lookup_val(envseg, "PATH");`
394	`if (pathptr == NULL) return;`	394	`if (pathptr == NULL) return;`
395		395
396	`/* try each path in %PATH% */`	396	`/* try each path in %PATH% */`
397	`for (;;) {`	397	`for (;;) {`
398	`for (i = 0;; i++) {`	398	`for (i = 0;; i++) {`
399	`buff[i] = *pathptr;`	399	`buff[i] = *pathptr;`
400	`if ((buff[i] == 0) \|\| (buff[i] == ';')) break;`	400	`if ((buff[i] == 0) \|\| (buff[i] == ';')) break;`
401	`pathptr++;`	401	`pathptr++;`
402	`}`	402	`}`
403	`buff[i] = 0;`	403	`buff[i] = 0;`
404	`lookup = lookup_cmd(cmdfile, cmd, buff, &ext);`	404	`lookup = lookup_cmd(cmdfile, cmd, buff, &ext);`
405	`if (lookup == 0) break;`	405	`if (lookup == 0) break;`
406	`if (lookup == -2) return;`	406	`if (lookup == -2) return;`
407	`if (*pathptr == ';') {`	407	`if (*pathptr == ';') {`
408	`pathptr++;`	408	`pathptr++;`
409	`} else {`	409	`} else {`
410	`return;`	410	`return;`
411	`}`	411	`}`
412	`}`	412	`}`
413		413
414	`RUNCMDFILE:`	414	`RUNCMDFILE:`
415		415
416	`/* special handling of batch files */`	416	`/* special handling of batch files */`
417	`if ((ext != NULL) && (imatch(ext, "bat"))) {`	417	`if ((ext != NULL) && (imatch(ext, "bat"))) {`
418	`/* copy truename of the bat file to rmod buff */`	418	`/* copy truename of the bat file to rmod buff */`
419	`for (i = 0; cmdfile[i] != 0; i++) rmod->batfile[i] = cmdfile[i];`	419	`for (i = 0; cmdfile[i] != 0; i++) rmod->batfile[i] = cmdfile[i];`
420	`rmod->batfile[i] = 0;`	420	`rmod->batfile[i] = 0;`
421	`/* copy args of the bat file to rmod buff */`	421	`/* copy args of the bat file to rmod buff */`
422	`for (i = 0; cmdtail[i] != 0; i++) rmod->batargs[i] = cmdtail[i];`	422	`for (i = 0; cmdtail[i] != 0; i++) rmod->batargs[i] = cmdtail[i];`
423	`/* reset the 'next line to execute' counter */`	423	`/* reset the 'next line to execute' counter */`
424	`rmod->batnextline = 0;`	424	`rmod->batnextline = 0;`
425	`/* remember the echo flag (in case bat file disables echo) */`	425	`/* remember the echo flag (in case bat file disables echo) */`
426	`rmod->flags &= ~FLAG_ECHO_BEFORE_BAT;`	426	`rmod->flags &= ~FLAG_ECHO_BEFORE_BAT;`
427	`if (rmod->flags & FLAG_ECHOFLAG) rmod->flags \|= FLAG_ECHO_BEFORE_BAT;`	427	`if (rmod->flags & FLAG_ECHOFLAG) rmod->flags \|= FLAG_ECHO_BEFORE_BAT;`
428	`return;`	428	`return;`
429	`}`	429	`}`
430		430
431	`/* copy full filename to execute */`	431	`/* copy full filename to execute */`
432	`for (i = 0; cmdfile[i] != 0; i++) rmod_execprog[i] = cmdfile[i];`	432	`for (i = 0; cmdfile[i] != 0; i++) rmod_execprog[i] = cmdfile[i];`
433	`rmod_execprog[i] = 0;`	433	`rmod_execprog[i] = 0;`
434		434
435	`/* copy cmdtail to rmod's PSP and compute its len */`	435	`/* copy cmdtail to rmod's PSP and compute its len */`
436	`for (i = 0; cmdtail[i] != 0; i++) rmod_cmdtail[i] = cmdtail[i];`	436	`for (i = 0; cmdtail[i] != 0; i++) rmod_cmdtail[i] = cmdtail[i];`
437	`rmod_cmdtail[i] = '\r';`	437	`rmod_cmdtail[i] = '\r';`
438	`rmod_cmdtail[-1] = i;`	438	`rmod_cmdtail[-1] = i;`
439		439
440	`/* set up rmod to execute the command */`	440	`/* set up rmod to execute the command */`
441		441
442	`ExecParam->envseg = envseg;`	442	`ExecParam->envseg = envseg;`
443	`ExecParam->cmdtail = (unsigned long)MK_FP(rmod->rmodseg, 0x80); /* farptr, must be in PSP format (lenbyte args \r) */`	443	`ExecParam->cmdtail = (unsigned long)MK_FP(rmod->rmodseg, 0x80); /* farptr, must be in PSP format (lenbyte args \r) */`
444	`ExecParam->fcb1 = 0; /* TODO farptr */`	444	`ExecParam->fcb1 = 0; /* TODO farptr */`
445	`ExecParam->fcb2 = 0; /* TODO farptr */`	445	`ExecParam->fcb2 = 0; /* TODO farptr */`
446	`exit(0); /* let rmod do the job now */`	446	`exit(0); /* let rmod do the job now */`
447	`}`	447	`}`
448		448
449		449
450	`static void set_comspec_to_self(unsigned short envseg) {`	450	`static void set_comspec_to_self(unsigned short envseg) {`
451	`unsigned short psp_envseg = (void )(0x2c); /* pointer to my env segment field in the PSP */`	451	`unsigned short psp_envseg = (void )(0x2c); /* pointer to my env segment field in the PSP */`
452	`char far myenv = MK_FP(psp_envseg, 0);`	452	`char far myenv = MK_FP(psp_envseg, 0);`
453	`unsigned short varcount;`	453	`unsigned short varcount;`
454	`char buff[256] = "COMSPEC=";`	454	`char buff[256] = "COMSPEC=";`
455	`char *buffptr = buff + 8;`	455	`char *buffptr = buff + 8;`
456	`/* who am i? look into my own environment, at the end of it should be my EXEPATH string */`	456	`/* who am i? look into my own environment, at the end of it should be my EXEPATH string */`
457	`while (*myenv != 0) {`	457	`while (*myenv != 0) {`
458	`/* consume a NULL-terminated string */`	458	`/* consume a NULL-terminated string */`
459	`while (*myenv != 0) myenv++;`	459	`while (*myenv != 0) myenv++;`
460	`/* move to next string */`	460	`/* move to next string */`
461	`myenv++;`	461	`myenv++;`
462	`}`	462	`}`
463	`/* get next word, if 1 then EXEPATH follows */`	463	`/* get next word, if 1 then EXEPATH follows */`
464	`myenv++;`	464	`myenv++;`
465	`varcount = *myenv;`	465	`varcount = *myenv;`
466	`myenv++;`	466	`myenv++;`
467	`varcount \|= (*myenv << 8);`	467	`varcount \|= (*myenv << 8);`
468	`myenv++;`	468	`myenv++;`
469	`if (varcount != 1) return; /* NO EXEPATH FOUND */`	469	`if (varcount != 1) return; /* NO EXEPATH FOUND */`
470	`while (*myenv != 0) {`	470	`while (*myenv != 0) {`
471	`buffptr = myenv;`	471	`buffptr = myenv;`
472	`buffptr++;`	472	`buffptr++;`
473	`myenv++;`	473	`myenv++;`
474	`}`	474	`}`
475	`*buffptr = 0;`	475	`*buffptr = 0;`
476	`/* printf("EXEPATH: '%s'\r\n", buff); */`	476	`/* printf("EXEPATH: '%s'\r\n", buff); */`
477	`env_setvar(envseg, buff);`	477	`env_setvar(envseg, buff);`
478	`}`	478	`}`
479		479
480		480
481	`/* wait for user input */`	481	`/* wait for user input */`
482	`static void cmdline_getinput(unsigned short inpseg, unsigned short inpoff) {`	482	`static void cmdline_getinput(unsigned short inpseg, unsigned short inpoff) {`
483	`_asm {`	483	`_asm {`
484	`push ax`	484	`push ax`
485	`push bx`	485	`push bx`
486	`push cx`	486	`push cx`
487	`push dx`	487	`push dx`
488	`push ds`	488	`push ds`
489		489
490	`/* is DOSKEY support present? (INT 2Fh, AX=4800h, returns non-zero in AL if present) */`	490	`/* is DOSKEY support present? (INT 2Fh, AX=4800h, returns non-zero in AL if present) */`
491	`mov ax, 0x4800`	491	`mov ax, 0x4800`
492	`int 0x2f`	492	`int 0x2f`
493	`mov bl, al /* save doskey status in BL */`	493	`mov bl, al /* save doskey status in BL */`
494		494
495	`/* set up buffered input to inpseg:inpoff */`	495	`/* set up buffered input to inpseg:inpoff */`
496	`mov ax, inpseg`	496	`mov ax, inpseg`
497	`push ax`	497	`push ax`
498	`pop ds`	498	`pop ds`
499	`mov dx, inpoff`	499	`mov dx, inpoff`
500		500

Subversion Repositories SvarDOS

(root)/svarcom/trunk/command.c @ 1202 – Rev 494 → 500