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.
 */
 
/*
 * SvarCOM is a command-line interpreter.
 *
 * a little memory area is allocated as high as possible. it contains:
 *  - a signature (like XMS drivers do)
 *  - a routine for exec'ing programs
 *  - a "last command" buffer for input history
 *
 * when svarcom starts, it tries locating the routine in memory.
 *
 * if found:
 *   waits for user input and processes it. if execing something is required, set the "next exec" field in routine's memory and quit.
 *
 * if not found:
 *   installs it by creating a new PSP, set int 22 vector to the routine, set my "parent PSP" to the routine
 *   and quit.
 *
 * PSP structure
 * http://www.piclist.com/techref/dos/psps.htm
 *
 *
 *
 * === MCB ===
 *
 * each time that DOS allocates memory, it prefixes the allocated memory with
 * a 16-bytes structure called a "Memory Control Block" (MCB). This control
 * block has the following structure:
 *
 * Offset  Size     Description
 *   00h   byte     'M' =  non-last member of the MCB chain
 *                  'Z' = indicates last entry in MCB chain
 *                  other values cause "Memory Allocation Failure" on exit
 *   01h   word     PSP segment address of the owner (Process Id)
 *                  possible values:
 *                    0 = free
 *                    8 = Allocated by DOS before first user pgm loaded
 *                    other = Process Id/PSP segment address of owner
 *   03h  word      number of paragraphs related to this MCB (excluding MCB)
 *   05h  11 bytes  reserved
 *   10h  ...       start of actual allocated memory block
 */
 
#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(void) {
  BUFFER[sizeof(BUFFER) - 1] = 0xC7;
  BUFFER[sizeof(BUFFER) - (CMDLINE_MAXLEN + 3)] = 0xC7;
}
 
 
/* checks for valguards at specific memory locations, returns 0 on success */
static int memguard_check(unsigned short rmodseg) {
  /* 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 (could be overwritten by cmdline) */
  if (BUFFER[sizeof(BUFFER) - 1] != 0xC7) {
    msg[22] = '2';
    outputnl(msg);
    return(2);
  }
  /* check that cmdline BUFFER's end hasn't been touched by something else */
  if (BUFFER[sizeof(BUFFER) - (CMDLINE_MAXLEN + 3)] != 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) {
  unsigned short i;
  const unsigned char *cmdlinelen = (unsigned char *)0x80;
  char *cmdline = (char *)0x81;
 
  memset(cfg, 0, sizeof(*cfg));
 
  /* set a NULL terminator on cmdline */
  cmdline[*cmdlinelen] = 0;
 
  for (i = 0;;) {
 
    /* skip over any leading spaces */
    for (;; i++) {
      if (cmdline[i] == 0) return;
      if (cmdline[i] != ' ') break;
    }
 
    if (cmdline[i] != '/') {
      output("Invalid parameter: ");
      outputnl(cmdline + i);
      /* exit(1); */
    } else {
      i++;        /* skip the slash */
      switch (cmdline[i]) {
        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 + i + 1;
          return;
 
        case 'e': /* preset the initial size of the environment block */
        case 'E':
          i++;
          if (cmdline[i] == ':') i++; /* could be /E:size */
          atous(&(cfg->envsiz), cmdline + i);
          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] command]");
          outputnl("");
          outputnl("/E:nnn     Sets the environment size to nnn bytes");
          outputnl("/P         Makes the new command interpreter permanent (can't exit)");
          outputnl("/C         Executes the specified command and returns");
          outputnl("/K         Executes the specified command and continues running");
          exit(1);
          break;
 
        default:
          output("Invalid switch:");
          output(" ");
          outputnl(cmdline + i);
          exit(1);
          break;
      }
    }
 
    /* move to next argument or quit processing if end of cmdline */
    for (i++; (cmdline[i] != 0) && (cmdline[i] != ' ') && (cmdline[i] != '/'); i++);
 
  }
}
 
 
/* 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 *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();
 
  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 */
  if (cfg.flags & 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);
 
    /* preset cmdline to point at the end of my general-purpose buffer (with
     * one extra byte for the NULL terminator and another for memguard val) */
    cmdline = BUFFER + sizeof(BUFFER) - (CMDLINE_MAXLEN + 2);
 
    /* (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) >= -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 485	Rev 490
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	`/*`	25	`/*`
26	`* SvarCOM is a command-line interpreter.`	26	`* SvarCOM is a command-line interpreter.`
27	`*`	27	`*`
28	`* a little memory area is allocated as high as possible. it contains:`	28	`* a little memory area is allocated as high as possible. it contains:`
29	`* - a signature (like XMS drivers do)`	29	`* - a signature (like XMS drivers do)`
30	`* - a routine for exec'ing programs`	30	`* - a routine for exec'ing programs`
31	`* - a "last command" buffer for input history`	31	`* - a "last command" buffer for input history`
32	`*`	32	`*`
33	`* when svarcom starts, it tries locating the routine in memory.`	33	`* when svarcom starts, it tries locating the routine in memory.`
34	`*`	34	`*`
35	`* if found:`	35	`* if found:`
36	`* waits for user input and processes it. if execing something is required, set the "next exec" field in routine's memory and quit.`	36	`* waits for user input and processes it. if execing something is required, set the "next exec" field in routine's memory and quit.`
37	`*`	37	`*`
38	`* if not found:`	38	`* if not found:`
39	`* installs it by creating a new PSP, set int 22 vector to the routine, set my "parent PSP" to the routine`	39	`* installs it by creating a new PSP, set int 22 vector to the routine, set my "parent PSP" to the routine`
40	`* and quit.`	40	`* and quit.`
41	`*`	41	`*`
42	`* PSP structure`	42	`* PSP structure`
43	`* http://www.piclist.com/techref/dos/psps.htm`	43	`* http://www.piclist.com/techref/dos/psps.htm`
44	`*`	44	`*`
45	`*`	45	`*`
46	`*`	46	`*`
47	`* === MCB ===`	47	`* === MCB ===`
48	`*`	48	`*`
49	`* each time that DOS allocates memory, it prefixes the allocated memory with`	49	`* each time that DOS allocates memory, it prefixes the allocated memory with`
50	`* a 16-bytes structure called a "Memory Control Block" (MCB). This control`	50	`* a 16-bytes structure called a "Memory Control Block" (MCB). This control`
51	`* block has the following structure:`	51	`* block has the following structure:`
52	`*`	52	`*`
53	`* Offset Size Description`	53	`* Offset Size Description`
54	`* 00h byte 'M' = non-last member of the MCB chain`	54	`* 00h byte 'M' = non-last member of the MCB chain`
55	`* 'Z' = indicates last entry in MCB chain`	55	`* 'Z' = indicates last entry in MCB chain`
56	`* other values cause "Memory Allocation Failure" on exit`	56	`* other values cause "Memory Allocation Failure" on exit`
57	`* 01h word PSP segment address of the owner (Process Id)`	57	`* 01h word PSP segment address of the owner (Process Id)`
58	`* possible values:`	58	`* possible values:`
59	`* 0 = free`	59	`* 0 = free`
60	`* 8 = Allocated by DOS before first user pgm loaded`	60	`* 8 = Allocated by DOS before first user pgm loaded`
61	`* other = Process Id/PSP segment address of owner`	61	`* other = Process Id/PSP segment address of owner`
62	`* 03h word number of paragraphs related to this MCB (excluding MCB)`	62	`* 03h word number of paragraphs related to this MCB (excluding MCB)`
63	`* 05h 11 bytes reserved`	63	`* 05h 11 bytes reserved`
64	`* 10h ... start of actual allocated memory block`	64	`* 10h ... start of actual allocated memory block`
65	`*/`	65	`*/`
66		66
67	`#include <i86.h>`	67	`#include <i86.h>`
68	`#include <dos.h>`	68	`#include <dos.h>`
69	`#include <stdio.h>`	69	`#include <stdio.h>`
70	`#include <stdlib.h>`	70	`#include <stdlib.h>`
71	`#include <string.h>`	71	`#include <string.h>`
72		72
73	`#include <process.h>`	73	`#include <process.h>`
74		74
75	`#include "cmd.h"`	75	`#include "cmd.h"`
76	`#include "env.h"`	76	`#include "env.h"`
77	`#include "helpers.h"`	77	`#include "helpers.h"`
78	`#include "redir.h"`	78	`#include "redir.h"`
79	`#include "rmodinit.h"`	79	`#include "rmodinit.h"`
80	`#include "sayonara.h"`	80	`#include "sayonara.h"`
81		81
82	`#include "rmodcore.h" /* rmod binary inside a BUFFER array */`	82	`#include "rmodcore.h" /* rmod binary inside a BUFFER array */`
83		83
84	`struct config {`	84	`struct config {`
85	`unsigned char flags; /* command.com flags, as defined in rmodinit.h */`	85	`unsigned char flags; /* command.com flags, as defined in rmodinit.h */`
86	`char *execcmd;`	86	`char *execcmd;`
87	`unsigned short envsiz;`	87	`unsigned short envsiz;`
88	`};`	88	`};`
89		89
-		90	`/* max length of the cmdline storage (bytes) - includes also max length of`
-		91	`* line loaded from a BAT file (no more than 255 bytes!) */`
-		92	`#define CMDLINE_MAXLEN 255`
-		93
-		94
-		95	`/* sets guard values at a few places in memory for later detection of`
-		96	`* overflows via memguard_check() */`
-		97	`static void memguard_set(void) {`
-		98	`BUFFER[sizeof(BUFFER) - 1] = 0xC7;`
-		99	`BUFFER[sizeof(BUFFER) - (CMDLINE_MAXLEN + 3)] = 0xC7;`
-		100	`}`
-		101
-		102
-		103	`/* checks for valguards at specific memory locations, returns 0 on success */`
-		104	`static int memguard_check(unsigned short rmodseg) {`
-		105	`/* check RMOD signature (would be overwritten in case of stack overflow */`
-		106	`static char msg[] = "!! MEMORY CORRUPTION ## DETECTED !!";`
-		107	`unsigned short far *rmodsig = MK_FP(rmodseg, 0x100 + 6);`
-		108	`if (*rmodsig != 0x2019) {`
-		109	`msg[22] = '1';`
-		110	`outputnl(msg);`
-		111	`printf("rmodseg = %04X ; rmodsig = %04X\r\n", rmodseg, rmodsig);`
-		112	`return(1);`
-		113	`}`
-		114	`/* check last BUFFER byte (could be overwritten by cmdline) */`
-		115	`if (BUFFER[sizeof(BUFFER) - 1] != 0xC7) {`
-		116	`msg[22] = '2';`
-		117	`outputnl(msg);`
-		118	`return(2);`
-		119	`}`
-		120	`/* check that cmdline BUFFER's end hasn't been touched by something else */`
-		121	`if (BUFFER[sizeof(BUFFER) - (CMDLINE_MAXLEN + 3)] != 0xC7) {`
-		122	`msg[22] = '3';`
-		123	`outputnl(msg);`
-		124	`return(3);`
-		125	`}`
-		126	`/* all good */`
-		127	`return(0);`
-		128	`}`
-		129
90		130
91	`/* parses command line the hard way (directly from PSP) */`	131	`/* parses command line the hard way (directly from PSP) */`
92	`static void parse_argv(struct config *cfg) {`	132	`static void parse_argv(struct config *cfg) {`
93	`unsigned short i;`	133	`unsigned short i;`
94	`const unsigned char cmdlinelen = (unsigned char )0x80;`	134	`const unsigned char cmdlinelen = (unsigned char )0x80;`
95	`char cmdline = (char )0x81;`	135	`char cmdline = (char )0x81;`
96		136
97	`memset(cfg, 0, sizeof(*cfg));`	137	`memset(cfg, 0, sizeof(*cfg));`
98		138
99	`/* set a NULL terminator on cmdline */`	139	`/* set a NULL terminator on cmdline */`
100	`cmdline[*cmdlinelen] = 0;`	140	`cmdline[*cmdlinelen] = 0;`
101		141
102	`for (i = 0;;) {`	142	`for (i = 0;;) {`
103		143
104	`/* skip over any leading spaces */`	144	`/* skip over any leading spaces */`
105	`for (;; i++) {`	145	`for (;; i++) {`
106	`if (cmdline[i] == 0) return;`	146	`if (cmdline[i] == 0) return;`
107	`if (cmdline[i] != ' ') break;`	147	`if (cmdline[i] != ' ') break;`
108	`}`	148	`}`
109		149
110	`if (cmdline[i] != '/') {`	150	`if (cmdline[i] != '/') {`
111	`output("Invalid parameter: ");`	151	`output("Invalid parameter: ");`
112	`outputnl(cmdline + i);`	152	`outputnl(cmdline + i);`
113	`/* exit(1); */`	153	`/* exit(1); */`
114	`} else {`	154	`} else {`
115	`i++; /* skip the slash */`	155	`i++; /* skip the slash */`
116	`switch (cmdline[i]) {`	156	`switch (cmdline[i]) {`
117	`case 'c': /* /C = execute command and quit */`	157	`case 'c': /* /C = execute command and quit */`
118	`case 'C':`	158	`case 'C':`
119	`cfg->flags \|= FLAG_EXEC_AND_QUIT;`	159	`cfg->flags \|= FLAG_EXEC_AND_QUIT;`
120	`/* FALLTHRU */`	160	`/* FALLTHRU */`
121	`case 'k': /* /K = execute command and keep running */`	161	`case 'k': /* /K = execute command and keep running */`
122	`case 'K':`	162	`case 'K':`
123	`cfg->execcmd = cmdline + i + 1;`	163	`cfg->execcmd = cmdline + i + 1;`
124	`return;`	164	`return;`
125		165
126	`case 'e': /* preset the initial size of the environment block */`	166	`case 'e': /* preset the initial size of the environment block */`
127	`case 'E':`	167	`case 'E':`
128	`i++;`	168	`i++;`
129	`if (cmdline[i] == ':') i++; /* could be /E:size */`	169	`if (cmdline[i] == ':') i++; /* could be /E:size */`
130	`atous(&(cfg->envsiz), cmdline + i);`	170	`atous(&(cfg->envsiz), cmdline + i);`
131	`if (cfg->envsiz < 64) cfg->envsiz = 0;`	171	`if (cfg->envsiz < 64) cfg->envsiz = 0;`
132	`break;`	172	`break;`
133		173
134	`case 'p': /* permanent shell (can't exit + run autoexec.bat) */`	174	`case 'p': /* permanent shell (can't exit + run autoexec.bat) */`
135	`case 'P':`	175	`case 'P':`
136	`cfg->flags \|= FLAG_PERMANENT;`	176	`cfg->flags \|= FLAG_PERMANENT;`
137	`break;`	177	`break;`
138		178
139	`case '?':`	179	`case '?':`
140	`outputnl("Starts the SvarCOM command interpreter");`	180	`outputnl("Starts the SvarCOM command interpreter");`
141	`outputnl("");`	181	`outputnl("");`
142	`outputnl("COMMAND /E:nnn [/[C\|K] command]");`	182	`outputnl("COMMAND /E:nnn [/[C\|K] command]");`
143	`outputnl("");`	183	`outputnl("");`
144	`outputnl("/E:nnn Sets the environment size to nnn bytes");`	184	`outputnl("/E:nnn Sets the environment size to nnn bytes");`
145	`outputnl("/P Makes the new command interpreter permanent (can't exit)");`	185	`outputnl("/P Makes the new command interpreter permanent (can't exit)");`
146	`outputnl("/C Executes the specified command and returns");`	186	`outputnl("/C Executes the specified command and returns");`
147	`outputnl("/K Executes the specified command and continues running");`	187	`outputnl("/K Executes the specified command and continues running");`
148	`exit(1);`	188	`exit(1);`
149	`break;`	189	`break;`
150		190
151	`default:`	191	`default:`
152	`output("Invalid switch:");`	192	`output("Invalid switch:");`
153	`output(" ");`	193	`output(" ");`
154	`outputnl(cmdline + i);`	194	`outputnl(cmdline + i);`
155	`exit(1);`	195	`exit(1);`
156	`break;`	196	`break;`
157	`}`	197	`}`
158	`}`	198	`}`
159		199
160	`/* move to next argument or quit processing if end of cmdline */`	200	`/* move to next argument or quit processing if end of cmdline */`
161	`for (i++; (cmdline[i] != 0) && (cmdline[i] != ' ') && (cmdline[i] != '/'); i++);`	201	`for (i++; (cmdline[i] != 0) && (cmdline[i] != ' ') && (cmdline[i] != '/'); i++);`
162		202
163	`}`	203	`}`
164	`}`	204	`}`
165		205
166		206
167	`/* builds the prompt string and displays it. buff is filled with a zero-terminated copy of the prompt. */`	207	`/* builds the prompt string and displays it. buff is filled with a zero-terminated copy of the prompt. */`
168	`static void build_and_display_prompt(char *buff, unsigned short envseg) {`	208	`static void build_and_display_prompt(char *buff, unsigned short envseg) {`
169	`char *s = buff;`	209	`char *s = buff;`
170	`/* locate the prompt variable or use the default pattern */`	210	`/* locate the prompt variable or use the default pattern */`
171	`const char far *fmt = env_lookup_val(envseg, "PROMPT");`	211	`const char far *fmt = env_lookup_val(envseg, "PROMPT");`
172	`if ((fmt == NULL) \|\| (fmt == 0)) fmt = "$p$g"; / fallback to default if empty */`	212	`if ((fmt == NULL) \|\| (fmt == 0)) fmt = "$p$g"; / fallback to default if empty */`
173	`/* build the prompt string based on pattern */`	213	`/* build the prompt string based on pattern */`
174	`for (; *fmt != 0; fmt++) {`	214	`for (; *fmt != 0; fmt++) {`
175	`if (*fmt != '$') {`	215	`if (*fmt != '$') {`
176	`s = fmt;`	216	`s = fmt;`
177	`s++;`	217	`s++;`
178	`continue;`	218	`continue;`
179	`}`	219	`}`
180	`/* escape code ($P, etc) */`	220	`/* escape code ($P, etc) */`
181	`fmt++;`	221	`fmt++;`
182	`switch (*fmt) {`	222	`switch (*fmt) {`
183	`case 'Q': /* $Q = = (equal sign) */`	223	`case 'Q': /* $Q = = (equal sign) */`
184	`case 'q':`	224	`case 'q':`
185	`*s = '=';`	225	`*s = '=';`
186	`s++;`	226	`s++;`
187	`break;`	227	`break;`
188	`case '$': /* $$ = $ (dollar sign) */`	228	`case '$': /* $$ = $ (dollar sign) */`
189	`*s = '$';`	229	`*s = '$';`
190	`s++;`	230	`s++;`
191	`break;`	231	`break;`
192	`case 'T': /* $t = current time */`	232	`case 'T': /* $t = current time */`
193	`case 't':`	233	`case 't':`
194	`s += sprintf(s, "00:00"); /* TODO */`	234	`s += sprintf(s, "00:00"); /* TODO */`
195	`break;`	235	`break;`
196	`case 'D': /* $D = current date */`	236	`case 'D': /* $D = current date */`
197	`case 'd':`	237	`case 'd':`
198	`s += sprintf(s, "1985-07-29"); /* TODO */`	238	`s += sprintf(s, "1985-07-29"); /* TODO */`
199	`break;`	239	`break;`
200	`case 'P': /* $P = current drive and path */`	240	`case 'P': /* $P = current drive and path */`
201	`case 'p':`	241	`case 'p':`
202	`_asm {`	242	`_asm {`
203	`mov ah, 0x19 /* DOS 1+ - GET CURRENT DRIVE */`	243	`mov ah, 0x19 /* DOS 1+ - GET CURRENT DRIVE */`
204	`int 0x21`	244	`int 0x21`
205	`mov bx, s`	245	`mov bx, s`
206	`mov [bx], al /* AL = drive (00 = A:, 01 = B:, etc */`	246	`mov [bx], al /* AL = drive (00 = A:, 01 = B:, etc */`
207	`}`	247	`}`
208	`*s += 'A';`	248	`*s += 'A';`
209	`s++;`	249	`s++;`
210	`*s = ':';`	250	`*s = ':';`
211	`s++;`	251	`s++;`
212	`*s = '\\';`	252	`*s = '\\';`
213	`s++;`	253	`s++;`
214	`_asm {`	254	`_asm {`
215	`mov ah, 0x47 /* DOS 2+ - CWD - GET CURRENT DIRECTORY */`	255	`mov ah, 0x47 /* DOS 2+ - CWD - GET CURRENT DIRECTORY */`
216	`xor dl,dl /* DL = drive number (00h = default, 01h = A:, etc) */`	256	`xor dl,dl /* DL = drive number (00h = default, 01h = A:, etc) */`
217	`mov si, s /* DS:SI -> 64-byte buffer for ASCIZ pathname */`	257	`mov si, s /* DS:SI -> 64-byte buffer for ASCIZ pathname */`
218	`int 0x21`	258	`int 0x21`
219	`}`	259	`}`
220	`while (s != 0) s++; / move ptr forward to end of pathname */`	260	`while (s != 0) s++; / move ptr forward to end of pathname */`
221	`break;`	261	`break;`
222	`case 'V': /* $V = DOS version number */`	262	`case 'V': /* $V = DOS version number */`
223	`case 'v':`	263	`case 'v':`
224	`s += sprintf(s, "VER"); /* TODO */`	264	`s += sprintf(s, "VER"); /* TODO */`
225	`break;`	265	`break;`
226	`case 'N': /* $N = current drive */`	266	`case 'N': /* $N = current drive */`
227	`case 'n':`	267	`case 'n':`
228	`_asm {`	268	`_asm {`
229	`mov ah, 0x19 /* DOS 1+ - GET CURRENT DRIVE */`	269	`mov ah, 0x19 /* DOS 1+ - GET CURRENT DRIVE */`
230	`int 0x21`	270	`int 0x21`
231	`mov bx, s`	271	`mov bx, s`
232	`mov [bx], al /* AL = drive (00 = A:, 01 = B:, etc */`	272	`mov [bx], al /* AL = drive (00 = A:, 01 = B:, etc */`
233	`}`	273	`}`
234	`*s += 'A';`	274	`*s += 'A';`
235	`s++;`	275	`s++;`
236	`break;`	276	`break;`
237	`case 'G': /* $G = > (greater-than sign) */`	277	`case 'G': /* $G = > (greater-than sign) */`
238	`case 'g':`	278	`case 'g':`
239	`*s = '>';`	279	`*s = '>';`
240	`s++;`	280	`s++;`
241	`break;`	281	`break;`
242	`case 'L': /* $L = < (less-than sign) */`	282	`case 'L': /* $L = < (less-than sign) */`
243	`case 'l':`	283	`case 'l':`
244	`*s = '<';`	284	`*s = '<';`
245	`s++;`	285	`s++;`
246	`break;`	286	`break;`
247	`case 'B': /* $B = \| (pipe) */`	287	`case 'B': /* $B = \| (pipe) */`
248	`case 'b':`	288	`case 'b':`
249	`*s = '\|';`	289	`*s = '\|';`
250	`s++;`	290	`s++;`
251	`break;`	291	`break;`
252	`case 'H': /* $H = backspace (erases previous character) */`	292	`case 'H': /* $H = backspace (erases previous character) */`
253	`case 'h':`	293	`case 'h':`
254	`*s = '\b';`	294	`*s = '\b';`
255	`s++;`	295	`s++;`
256	`break;`	296	`break;`
257	`case 'E': /* $E = Escape code (ASCII 27) */`	297	`case 'E': /* $E = Escape code (ASCII 27) */`
258	`case 'e':`	298	`case 'e':`
259	`*s = 27;`	299	`*s = 27;`
260	`s++;`	300	`s++;`
261	`break;`	301	`break;`
262	`case '_': /* $_ = CR+LF */`	302	`case '_': /* $_ = CR+LF */`
263	`*s = '\r';`	303	`*s = '\r';`
264	`s++;`	304	`s++;`
265	`*s = '\n';`	305	`*s = '\n';`
266	`s++;`	306	`s++;`
267	`break;`	307	`break;`
268	`}`	308	`}`
269	`}`	309	`}`
270	`*s = 0;`	310	`*s = 0;`
271	`output(buff);`	311	`output(buff);`
272	`}`	312	`}`
273		313
274		314
275	`/* tries locating executable fname in path and fille res with result. returns 0 on success,`	315	`/* tries locating executable fname in path and fille res with result. returns 0 on success,`
276	`* -1 on failed match and -2 on failed match + "don't even try with other paths"`	316	`* -1 on failed match and -2 on failed match + "don't even try with other paths"`
277	`* format is filled the offset where extension starts in fname (-1 if not found) */`	317	`* format is filled the offset where extension starts in fname (-1 if not found) */`
278	`int lookup_cmd(char res, const char fname, const char path, const char *extptr) {`	318	`int lookup_cmd(char res, const char fname, const char path, const char *extptr) {`
279	`unsigned short lastbslash = 0xffff;`	319	`unsigned short lastbslash = 0xffff;`
280	`unsigned short i, len;`	320	`unsigned short i, len;`
281	`unsigned char explicitpath = 0;`	321	`unsigned char explicitpath = 0;`
282		322
283	`/* does the original fname had an explicit path prefix or explicit ext? */`	323	`/* does the original fname had an explicit path prefix or explicit ext? */`
284	`*extptr = NULL;`	324	`*extptr = NULL;`
285	`for (i = 0; fname[i] != 0; i++) {`	325	`for (i = 0; fname[i] != 0; i++) {`
286	`switch (fname[i]) {`	326	`switch (fname[i]) {`
287	`case ':':`	327	`case ':':`
288	`case '\\':`	328	`case '\\':`
289	`explicitpath = 1;`	329	`explicitpath = 1;`
290	`extptr = NULL; / extension is the last dot AFTER all path delimiters */`	330	`extptr = NULL; / extension is the last dot AFTER all path delimiters */`
291	`break;`	331	`break;`
292	`case '.':`	332	`case '.':`
293	`*extptr = fname + i + 1;`	333	`*extptr = fname + i + 1;`
294	`break;`	334	`break;`
295	`}`	335	`}`
296	`}`	336	`}`
297		337
298	`/* normalize filename */`	338	`/* normalize filename */`
299	`if (file_truename(fname, res) != 0) return(-2);`	339	`if (file_truename(fname, res) != 0) return(-2);`
300		340
301	`/* printf("truename: %s\r\n", res); */`	341	`/* printf("truename: %s\r\n", res); */`
302		342
303	`/* figure out where the command starts and if it has an explicit extension */`	343	`/* figure out where the command starts and if it has an explicit extension */`
304	`for (len = 0; res[len] != 0; len++) {`	344	`for (len = 0; res[len] != 0; len++) {`
305	`switch (res[len]) {`	345	`switch (res[len]) {`
306	`case '?': /* abort on any wildcard character */`	346	`case '?': /* abort on any wildcard character */`
307	`case '*':`	347	`case '*':`
308	`return(-2);`	348	`return(-2);`
309	`case '\\':`	349	`case '\\':`
310	`lastbslash = len;`	350	`lastbslash = len;`
311	`break;`	351	`break;`
312	`}`	352	`}`
313	`}`	353	`}`
314		354
315	`/* printf("lastbslash=%u\r\n", lastbslash); */`	355	`/* printf("lastbslash=%u\r\n", lastbslash); */`
316		356
317	`/* if no path prefix in fname (':' or backslash), then assemble path+filename */`	357	`/* if no path prefix in fname (':' or backslash), then assemble path+filename */`
318	`if (!explicitpath) {`	358	`if (!explicitpath) {`
319	`if (path != NULL) {`	359	`if (path != NULL) {`
320	`i = strlen(path);`	360	`i = strlen(path);`
321	`} else {`	361	`} else {`
322	`i = 0;`	362	`i = 0;`
323	`}`	363	`}`
324	`if ((i != 0) && (path[i - 1] != '\\')) i++; /* add a byte for inserting a bkslash after path */`	364	`if ((i != 0) && (path[i - 1] != '\\')) i++; /* add a byte for inserting a bkslash after path */`
325	`memmove(res + i, res + lastbslash + 1, len - lastbslash);`	365	`memmove(res + i, res + lastbslash + 1, len - lastbslash);`
326	`if (i != 0) {`	366	`if (i != 0) {`
327	`memmove(res, path, i);`	367	`memmove(res, path, i);`
328	`res[i - 1] = '\\';`	368	`res[i - 1] = '\\';`
329	`}`	369	`}`
330	`}`	370	`}`
331		371
332	`/* if no extension was initially provided, try matching COM, EXE, BAT */`	372	`/* if no extension was initially provided, try matching COM, EXE, BAT */`
333	`if (*extptr == NULL) {`	373	`if (*extptr == NULL) {`
334	`const char *ext[] = {".COM", ".EXE", ".BAT", NULL};`	374	`const char *ext[] = {".COM", ".EXE", ".BAT", NULL};`
335	`len = strlen(res);`	375	`len = strlen(res);`
336	`for (i = 0; ext[i] != NULL; i++) {`	376	`for (i = 0; ext[i] != NULL; i++) {`
337	`strcpy(res + len, ext[i]);`	377	`strcpy(res + len, ext[i]);`
338	`/* printf("? '%s'\r\n", res); */`	378	`/* printf("? '%s'\r\n", res); */`
339	`*extptr = ext[i] + 1;`	379	`*extptr = ext[i] + 1;`
340	`if (file_getattr(res) >= 0) return(0);`	380	`if (file_getattr(res) >= 0) return(0);`
341	`}`	381	`}`
342	`} else { /* try finding it as-is */`	382	`} else { /* try finding it as-is */`
343	`/* printf("? '%s'\r\n", res); */`	383	`/* printf("? '%s'\r\n", res); */`
344	`if (file_getattr(res) >= 0) return(0);`	384	`if (file_getattr(res) >= 0) return(0);`
345	`}`	385	`}`
346		386
347	`/* not found */`	387	`/* not found */`
348	`if (explicitpath) return(-2); /* don't bother trying other paths, the caller had its own path preset anyway */`	388	`if (explicitpath) return(-2); /* don't bother trying other paths, the caller had its own path preset anyway */`
349	`return(-1);`	389	`return(-1);`
350	`}`	390	`}`
351		391
352		392
353	`static void run_as_external(char buff, const char cmdline, unsigned short envseg, struct rmod_props far *rmod) {`	393	`static void run_as_external(char buff, const char cmdline, unsigned short envseg, struct rmod_props far *rmod) {`
354	`char *cmdfile = buff + 512;`	394	`char *cmdfile = buff + 512;`
355	`const char far *pathptr;`	395	`const char far *pathptr;`
356	`int lookup;`	396	`int lookup;`
357	`unsigned short i;`	397	`unsigned short i;`
358	`const char *ext;`	398	`const char *ext;`
359	`char *cmd = buff + 256;`	399	`char *cmd = buff + 256;`
360	`const char *cmdtail;`	400	`const char *cmdtail;`
361	`char far *rmod_execprog = MK_FP(rmod->rmodseg, RMOD_OFFSET_EXECPROG);`	401	`char far *rmod_execprog = MK_FP(rmod->rmodseg, RMOD_OFFSET_EXECPROG);`
362	`char far *rmod_cmdtail = MK_FP(rmod->rmodseg, 0x81);`	402	`char far *rmod_cmdtail = MK_FP(rmod->rmodseg, 0x81);`
363	`_Packed struct {`	403	`_Packed struct {`
364	`unsigned short envseg;`	404	`unsigned short envseg;`
365	`unsigned long cmdtail;`	405	`unsigned long cmdtail;`
366	`unsigned long fcb1;`	406	`unsigned long fcb1;`
367	`unsigned long fcb2;`	407	`unsigned long fcb2;`
368	`} far *ExecParam = MK_FP(rmod->rmodseg, RMOD_OFFSET_EXECPARAM);`	408	`} far *ExecParam = MK_FP(rmod->rmodseg, RMOD_OFFSET_EXECPARAM);`
369		409
370	`/* find cmd and cmdtail */`	410	`/* find cmd and cmdtail */`
371	`i = 0;`	411	`i = 0;`
372	`cmdtail = cmdline;`	412	`cmdtail = cmdline;`
373	`while (cmdtail == ' ') cmdtail++; / skip any leading spaces */`	413	`while (cmdtail == ' ') cmdtail++; / skip any leading spaces */`
374	`while ((cmdtail != ' ') && (cmdtail != '/') && (cmdtail != '+') && (cmdtail != 0)) {`	414	`while ((cmdtail != ' ') && (cmdtail != '/') && (cmdtail != '+') && (cmdtail != 0)) {`
375	`cmd[i++] = *cmdtail;`	415	`cmd[i++] = *cmdtail;`
376	`cmdtail++;`	416	`cmdtail++;`
377	`}`	417	`}`
378	`cmd[i] = 0;`	418	`cmd[i] = 0;`
379		419
380	`/* is this a command in curdir? */`	420	`/* is this a command in curdir? */`
381	`lookup = lookup_cmd(cmdfile, cmd, NULL, &ext);`	421	`lookup = lookup_cmd(cmdfile, cmd, NULL, &ext);`
382	`if (lookup == 0) {`	422	`if (lookup == 0) {`
383	`/* printf("FOUND LOCAL EXEC FILE: '%s'\r\n", cmdfile); */`	423	`/* printf("FOUND LOCAL EXEC FILE: '%s'\r\n", cmdfile); */`
384	`goto RUNCMDFILE;`	424	`goto RUNCMDFILE;`
385	`} else if (lookup == -2) {`	425	`} else if (lookup == -2) {`
386	`/* puts("NOT FOUND"); */`	426	`/* puts("NOT FOUND"); */`
387	`return;`	427	`return;`
388	`}`	428	`}`
389		429
390	`/* try matching something in PATH */`	430	`/* try matching something in PATH */`
391	`pathptr = env_lookup_val(envseg, "PATH");`	431	`pathptr = env_lookup_val(envseg, "PATH");`
392	`if (pathptr == NULL) return;`	432	`if (pathptr == NULL) return;`
393		433
394	`/* try each path in %PATH% */`	434	`/* try each path in %PATH% */`
395	`for (;;) {`	435	`for (;;) {`
396	`for (i = 0;; i++) {`	436	`for (i = 0;; i++) {`
397	`buff[i] = *pathptr;`	437	`buff[i] = *pathptr;`
398	`if ((buff[i] == 0) \|\| (buff[i] == ';')) break;`	438	`if ((buff[i] == 0) \|\| (buff[i] == ';')) break;`
399	`pathptr++;`	439	`pathptr++;`
400	`}`	440	`}`
401	`buff[i] = 0;`	441	`buff[i] = 0;`
402	`lookup = lookup_cmd(cmdfile, cmd, buff, &ext);`	442	`lookup = lookup_cmd(cmdfile, cmd, buff, &ext);`
403	`if (lookup == 0) break;`	443	`if (lookup == 0) break;`
404	`if (lookup == -2) return;`	444	`if (lookup == -2) return;`
405	`if (*pathptr == ';') {`	445	`if (*pathptr == ';') {`
406	`pathptr++;`	446	`pathptr++;`
407	`} else {`	447	`} else {`
408	`return;`	448	`return;`
409	`}`	449	`}`
410	`}`	450	`}`
411		451
412	`RUNCMDFILE:`	452	`RUNCMDFILE:`
413		453
414	`/* special handling of batch files */`	454	`/* special handling of batch files */`
415	`if ((ext != NULL) && (imatch(ext, "bat"))) {`	455	`if ((ext != NULL) && (imatch(ext, "bat"))) {`
416	`/* copy truename of the bat file to rmod buff */`	456	`/* copy truename of the bat file to rmod buff */`
417	`for (i = 0; cmdfile[i] != 0; i++) rmod->batfile[i] = cmdfile[i];`	457	`for (i = 0; cmdfile[i] != 0; i++) rmod->batfile[i] = cmdfile[i];`
418	`rmod->batfile[i] = 0;`	458	`rmod->batfile[i] = 0;`
419	`/* copy args of the bat file to rmod buff */`	459	`/* copy args of the bat file to rmod buff */`
420	`for (i = 0; cmdtail[i] != 0; i++) rmod->batargs[i] = cmdtail[i];`	460	`for (i = 0; cmdtail[i] != 0; i++) rmod->batargs[i] = cmdtail[i];`
421	`/* reset the 'next line to execute' counter */`	461	`/* reset the 'next line to execute' counter */`
422	`rmod->batnextline = 0;`	462	`rmod->batnextline = 0;`
423	`/* remember the echo flag (in case bat file disables echo) */`	463	`/* remember the echo flag (in case bat file disables echo) */`
424	`rmod->flags &= ~FLAG_ECHO_BEFORE_BAT;`	464	`rmod->flags &= ~FLAG_ECHO_BEFORE_BAT;`
425	`if (rmod->flags & FLAG_ECHOFLAG) rmod->flags \|= FLAG_ECHO_BEFORE_BAT;`	465	`if (rmod->flags & FLAG_ECHOFLAG) rmod->flags \|= FLAG_ECHO_BEFORE_BAT;`
426	`return;`	466	`return;`
427	`}`	467	`}`
428		468
429	`/* copy full filename to execute */`	469	`/* copy full filename to execute */`
430	`for (i = 0; cmdfile[i] != 0; i++) rmod_execprog[i] = cmdfile[i];`	470	`for (i = 0; cmdfile[i] != 0; i++) rmod_execprog[i] = cmdfile[i];`
431	`rmod_execprog[i] = 0;`	471	`rmod_execprog[i] = 0;`
432		472
433	`/* copy cmdtail to rmod's PSP and compute its len */`	473	`/* copy cmdtail to rmod's PSP and compute its len */`
434	`for (i = 0; cmdtail[i] != 0; i++) rmod_cmdtail[i] = cmdtail[i];`	474	`for (i = 0; cmdtail[i] != 0; i++) rmod_cmdtail[i] = cmdtail[i];`
435	`rmod_cmdtail[i] = '\r';`	475	`rmod_cmdtail[i] = '\r';`
436	`rmod_cmdtail[-1] = i;`	476	`rmod_cmdtail[-1] = i;`
437		477
438	`/* set up rmod to execute the command */`	478	`/* set up rmod to execute the command */`
439		479
440	`ExecParam->envseg = envseg;`	480	`ExecParam->envseg = envseg;`
441	`ExecParam->cmdtail = (unsigned long)MK_FP(rmod->rmodseg, 0x80); /* farptr, must be in PSP format (lenbyte args \r) */`	481	`ExecParam->cmdtail = (unsigned long)MK_FP(rmod->rmodseg, 0x80); /* farptr, must be in PSP format (lenbyte args \r) */`
442	`ExecParam->fcb1 = 0; /* TODO farptr */`	482	`ExecParam->fcb1 = 0; /* TODO farptr */`
443	`ExecParam->fcb2 = 0; /* TODO farptr */`	483	`ExecParam->fcb2 = 0; /* TODO farptr */`
444	`exit(0); /* let rmod do the job now */`	484	`exit(0); /* let rmod do the job now */`
445	`}`	485	`}`
446		486
447		487
448	`static void set_comspec_to_self(unsigned short envseg) {`	488	`static void set_comspec_to_self(unsigned short envseg) {`
449	`unsigned short psp_envseg = (void )(0x2c); /* pointer to my env segment field in the PSP */`	489	`unsigned short psp_envseg = (void )(0x2c); /* pointer to my env segment field in the PSP */`
450	`char far myenv = MK_FP(psp_envseg, 0);`	490	`char far myenv = MK_FP(psp_envseg, 0);`
451	`unsigned short varcount;`	491	`unsigned short varcount;`
452	`char buff[256] = "COMSPEC=";`	492	`char buff[256] = "COMSPEC=";`
453	`char *buffptr = buff + 8;`	493	`char *buffptr = buff + 8;`
454	`/* who am i? look into my own environment, at the end of it should be my EXEPATH string */`	494	`/* who am i? look into my own environment, at the end of it should be my EXEPATH string */`
455	`while (*myenv != 0) {`	495	`while (*myenv != 0) {`
456	`/* consume a NULL-terminated string */`	496	`/* consume a NULL-terminated string */`
457	`while (*myenv != 0) myenv++;`	497	`while (*myenv != 0) myenv++;`
458	`/* move to next string */`	498	`/* move to next string */`
459	`myenv++;`	499	`myenv++;`
460	`}`	500	`}`

Subversion Repositories SvarDOS

(root)/svarcom/trunk/command.c @ 1095 – Rev 485 → 490