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"
 
 
struct config {
  unsigned char flags; /* command.com flags, as defined in rmodinit.h */
  char *execcmd;
  unsigned short envsiz;
};
 
 
/* 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) */
        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++);
 
  }
}
 
 
static void buildprompt(char *s, unsigned short envseg) {
  /* 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 '_':  /* $_ = CR+LF */
        *s = '\r';
        s++;
        *s = '\n';
        s++;
        break;
    }
  }
  *s = '$';
}
 
 
/* 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 far *cmdline, unsigned short envseg, struct rmod_props far *rmod) {
  char const **argvlist = (void *)(buff + 512);
  char *cmdfile = buff + 1024;
  const char far *pathptr;
  int lookup;
  unsigned short i;
  const char *ext;
  const char far *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);
 
  cmd_explode(buff + 2048, cmdline, argvlist);
 
  /* for (i = 0; argvlist[i] != NULL; i++) printf("arg #%d = '%s'\r\n", i, argvlist[i]); */
 
  /* is this a command in curdir? */
  lookup = lookup_cmd(cmdfile, argvlist[0], 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, argvlist[0], buff, &ext);
    if (lookup == 0) break;
    if (lookup == -2) return;
    if (*pathptr == ';') {
      pathptr++;
    } else {
      return;
    }
  }
 
  RUNCMDFILE:
 
 
  /* TODO special handling of batch files */
  if ((ext != NULL) && (imatch(ext, "bat"))) {
    outputnl("batch processing not supported yet");
    return;
  }
 
  /* find cmdtail */
  cmdtail = cmdline;
  while (*cmdtail == ' ') cmdtail++;
  while ((*cmdtail != ' ') && (*cmdtail != '/') && (*cmdtail != '+') && (*cmdtail != 0)) {
    cmdtail++;
  }
 
  /* 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
  }
}
 
 
int main(void) {
  static struct config cfg;
 
  static unsigned short far *rmod_envseg;
  static unsigned short far *lastexitcode;
  static unsigned char BUFFER[4096];
  static struct rmod_props far *rmod;
 
 
 
  rmod = rmod_find();
  if (rmod == NULL) {
    rmod = rmod_install(cfg.envsiz);
    if (rmod == NULL) {
      outputnl("ERROR: rmod_install() failed");
      return(1);
    }
    /* look at command line parameters */
    parse_argv(&cfg);
    /* copy flags to rmod's storage */
    rmod->flags = cfg.flags;
    /* 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) {
      printf("rmod + FLAG_EXEC_AND_QUIT\r\n");
      sayonara(rmod);
    }
  }
 
 
  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);
  }*/
 
  do {
    char far *cmdline = rmod->inputbuf + 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 (rmod->echoflag != 0) outputnl(""); /* terminate the previous command with a CR/LF */
 
    SKIP_NEWLINE:
 
    /* print shell prompt (only if ECHO is enabled) */
    if (rmod->echoflag != 0) {
      char *promptptr = BUFFER;
      buildprompt(promptptr, *rmod_envseg);
      _asm {
        push ax
        push dx
        mov ah, 0x09
        mov dx, promptptr
        int 0x21
        pop dx
        pop ax
      }
    }
 
    /* revert input history terminator to \r */
    if (cmdline[-1] != 0) {
      cmdline[(unsigned short)(cmdline[-1])] = '\r';
    }
 
    /* wait for user command line */
    cmdline_getinput(FP_SEG(rmod->inputbuf), FP_OFF(rmod->inputbuf));
 
    /* if nothing entered, loop again (but without appending an extra CR/LF) */
    if (cmdline[-1] == 0) goto SKIP_NEWLINE;
 
    /* replace \r by a zero terminator */
    cmdline[(unsigned char)(cmdline[-1])] = 0;
 
    /* 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);
 
    /* revert stdout (in case it was 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 464	Rev 465
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		82
83	`struct config {`	83	`struct config {`
84	`unsigned char flags; /* command.com flags, as defined in rmodinit.h */`	84	`unsigned char flags; /* command.com flags, as defined in rmodinit.h */`
85	`char *execcmd;`	85	`char *execcmd;`
86	`unsigned short envsiz;`	86	`unsigned short envsiz;`
87	`};`	87	`};`
88		88
89		89
90	`/* parses command line the hard way (directly from PSP) */`	90	`/* parses command line the hard way (directly from PSP) */`
91	`static void parse_argv(struct config *cfg) {`	91	`static void parse_argv(struct config *cfg) {`
92	`unsigned short i;`	92	`unsigned short i;`
93	`const unsigned char cmdlinelen = (unsigned char )0x80;`	93	`const unsigned char cmdlinelen = (unsigned char )0x80;`
94	`char cmdline = (char )0x81;`	94	`char cmdline = (char )0x81;`
95		95
96	`memset(cfg, 0, sizeof(*cfg));`	96	`memset(cfg, 0, sizeof(*cfg));`
97		97
98	`/* set a NULL terminator on cmdline */`	98	`/* set a NULL terminator on cmdline */`
99	`cmdline[*cmdlinelen] = 0;`	99	`cmdline[*cmdlinelen] = 0;`
100		100
101	`for (i = 0;;) {`	101	`for (i = 0;;) {`
102		102
103	`/* skip over any leading spaces */`	103	`/* skip over any leading spaces */`
104	`for (;; i++) {`	104	`for (;; i++) {`
105	`if (cmdline[i] == 0) return;`	105	`if (cmdline[i] == 0) return;`
106	`if (cmdline[i] != ' ') break;`	106	`if (cmdline[i] != ' ') break;`
107	`}`	107	`}`
108		108
109	`if (cmdline[i] != '/') {`	109	`if (cmdline[i] != '/') {`
110	`output("Invalid parameter: ");`	110	`output("Invalid parameter: ");`
111	`outputnl(cmdline + i);`	111	`outputnl(cmdline + i);`
112	`/* exit(1); */`	112	`/* exit(1); */`
113	`} else {`	113	`} else {`
114	`i++; /* skip the slash */`	114	`i++; /* skip the slash */`
115	`switch (cmdline[i]) {`	115	`switch (cmdline[i]) {`
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 + i + 1;`	122	`cfg->execcmd = cmdline + i + 1;`
123	`return;`	123	`return;`
124		124
125	`case 'e': /* preset the initial size of the environment block */`	125	`case 'e': /* preset the initial size of the environment block */`
126	`case 'E':`	126	`case 'E':`
127	`i++;`	127	`i++;`
128	`if (cmdline[i] == ':') i++; /* could be /E:size */`	128	`if (cmdline[i] == ':') i++; /* could be /E:size */`
129	`atous(&(cfg->envsiz), cmdline + i);`	129	`atous(&(cfg->envsiz), cmdline + i);`
130	`if (cfg->envsiz < 64) cfg->envsiz = 0;`	130	`if (cfg->envsiz < 64) cfg->envsiz = 0;`
131	`break;`	131	`break;`
132		132
133	`case 'p': /* permanent shell (can't exit) */`	133	`case 'p': /* permanent shell (can't exit) */`
134	`case 'P':`	134	`case 'P':`
135	`cfg->flags \|= FLAG_PERMANENT;`	135	`cfg->flags \|= FLAG_PERMANENT;`
136	`break;`	136	`break;`
137		137
138	`case '?':`	138	`case '?':`
139	`outputnl("Starts the SvarCOM command interpreter");`	139	`outputnl("Starts the SvarCOM command interpreter");`
140	`outputnl("");`	140	`outputnl("");`
141	`outputnl("COMMAND /E:nnn [/[C\|K] command]");`	141	`outputnl("COMMAND /E:nnn [/[C\|K] command]");`
142	`outputnl("");`	142	`outputnl("");`
143	`outputnl("/E:nnn Sets the environment size to nnn bytes");`	143	`outputnl("/E:nnn Sets the environment size to nnn bytes");`
144	`outputnl("/P Makes the new command interpreter permanent (can't exit)");`	144	`outputnl("/P Makes the new command interpreter permanent (can't exit)");`
145	`outputnl("/C Executes the specified command and returns");`	145	`outputnl("/C Executes the specified command and returns");`
146	`outputnl("/K Executes the specified command and continues running");`	146	`outputnl("/K Executes the specified command and continues running");`
147	`exit(1);`	147	`exit(1);`
148	`break;`	148	`break;`
149		149
150	`default:`	150	`default:`
151	`output("Invalid switch:");`	151	`output("Invalid switch:");`
152	`output(" ");`	152	`output(" ");`
153	`outputnl(cmdline + i);`	153	`outputnl(cmdline + i);`
154	`exit(1);`	154	`exit(1);`
155	`break;`	155	`break;`
156	`}`	156	`}`
157	`}`	157	`}`
158		158
159	`/* move to next argument or quit processing if end of cmdline */`	159	`/* move to next argument or quit processing if end of cmdline */`
160	`for (i++; (cmdline[i] != 0) && (cmdline[i] != ' ') && (cmdline[i] != '/'); i++);`	160	`for (i++; (cmdline[i] != 0) && (cmdline[i] != ' ') && (cmdline[i] != '/'); i++);`
161		161
162	`}`	162	`}`
163	`}`	163	`}`
164		164
165		165
166	`static void buildprompt(char *s, unsigned short envseg) {`	166	`static void buildprompt(char *s, unsigned short envseg) {`
167	`/* locate the prompt variable or use the default pattern */`	167	`/* locate the prompt variable or use the default pattern */`
168	`const char far *fmt = env_lookup_val(envseg, "PROMPT");`	168	`const char far *fmt = env_lookup_val(envseg, "PROMPT");`
169	`if ((fmt == NULL) \|\| (fmt == 0)) fmt = "$p$g"; / fallback to default if empty */`	169	`if ((fmt == NULL) \|\| (fmt == 0)) fmt = "$p$g"; / fallback to default if empty */`
170	`/* build the prompt string based on pattern */`	170	`/* build the prompt string based on pattern */`
171	`for (; *fmt != 0; fmt++) {`	171	`for (; *fmt != 0; fmt++) {`
172	`if (*fmt != '$') {`	172	`if (*fmt != '$') {`
173	`s = fmt;`	173	`s = fmt;`
174	`s++;`	174	`s++;`
175	`continue;`	175	`continue;`
176	`}`	176	`}`
177	`/* escape code ($P, etc) */`	177	`/* escape code ($P, etc) */`
178	`fmt++;`	178	`fmt++;`
179	`switch (*fmt) {`	179	`switch (*fmt) {`
180	`case 'Q': /* $Q = = (equal sign) */`	180	`case 'Q': /* $Q = = (equal sign) */`
181	`case 'q':`	181	`case 'q':`
182	`*s = '=';`	182	`*s = '=';`
183	`s++;`	183	`s++;`
184	`break;`	184	`break;`
185	`case '$': /* $$ = $ (dollar sign) */`	185	`case '$': /* $$ = $ (dollar sign) */`
186	`*s = '$';`	186	`*s = '$';`
187	`s++;`	187	`s++;`
188	`break;`	188	`break;`
189	`case 'T': /* $t = current time */`	189	`case 'T': /* $t = current time */`
190	`case 't':`	190	`case 't':`
191	`s += sprintf(s, "00:00"); /* TODO */`	191	`s += sprintf(s, "00:00"); /* TODO */`
192	`break;`	192	`break;`
193	`case 'D': /* $D = current date */`	193	`case 'D': /* $D = current date */`
194	`case 'd':`	194	`case 'd':`
195	`s += sprintf(s, "1985-07-29"); /* TODO */`	195	`s += sprintf(s, "1985-07-29"); /* TODO */`
196	`break;`	196	`break;`
197	`case 'P': /* $P = current drive and path */`	197	`case 'P': /* $P = current drive and path */`
198	`case 'p':`	198	`case 'p':`
199	`_asm {`	199	`_asm {`
200	`mov ah, 0x19 /* DOS 1+ - GET CURRENT DRIVE */`	200	`mov ah, 0x19 /* DOS 1+ - GET CURRENT DRIVE */`
201	`int 0x21`	201	`int 0x21`
202	`mov bx, s`	202	`mov bx, s`
203	`mov [bx], al /* AL = drive (00 = A:, 01 = B:, etc */`	203	`mov [bx], al /* AL = drive (00 = A:, 01 = B:, etc */`
204	`}`	204	`}`
205	`*s += 'A';`	205	`*s += 'A';`
206	`s++;`	206	`s++;`
207	`*s = ':';`	207	`*s = ':';`
208	`s++;`	208	`s++;`
209	`*s = '\\';`	209	`*s = '\\';`
210	`s++;`	210	`s++;`
211	`_asm {`	211	`_asm {`
212	`mov ah, 0x47 /* DOS 2+ - CWD - GET CURRENT DIRECTORY */`	212	`mov ah, 0x47 /* DOS 2+ - CWD - GET CURRENT DIRECTORY */`
213	`xor dl,dl /* DL = drive number (00h = default, 01h = A:, etc) */`	213	`xor dl,dl /* DL = drive number (00h = default, 01h = A:, etc) */`
214	`mov si, s /* DS:SI -> 64-byte buffer for ASCIZ pathname */`	214	`mov si, s /* DS:SI -> 64-byte buffer for ASCIZ pathname */`
215	`int 0x21`	215	`int 0x21`
216	`}`	216	`}`
217	`while (s != 0) s++; / move ptr forward to end of pathname */`	217	`while (s != 0) s++; / move ptr forward to end of pathname */`
218	`break;`	218	`break;`
219	`case 'V': /* $V = DOS version number */`	219	`case 'V': /* $V = DOS version number */`
220	`case 'v':`	220	`case 'v':`
221	`s += sprintf(s, "VER"); /* TODO */`	221	`s += sprintf(s, "VER"); /* TODO */`
222	`break;`	222	`break;`
223	`case 'N': /* $N = current drive */`	223	`case 'N': /* $N = current drive */`
224	`case 'n':`	224	`case 'n':`
225	`_asm {`	225	`_asm {`
226	`mov ah, 0x19 /* DOS 1+ - GET CURRENT DRIVE */`	226	`mov ah, 0x19 /* DOS 1+ - GET CURRENT DRIVE */`
227	`int 0x21`	227	`int 0x21`
228	`mov bx, s`	228	`mov bx, s`
229	`mov [bx], al /* AL = drive (00 = A:, 01 = B:, etc */`	229	`mov [bx], al /* AL = drive (00 = A:, 01 = B:, etc */`
230	`}`	230	`}`
231	`*s += 'A';`	231	`*s += 'A';`
232	`s++;`	232	`s++;`
233	`break;`	233	`break;`
234	`case 'G': /* $G = > (greater-than sign) */`	234	`case 'G': /* $G = > (greater-than sign) */`
235	`case 'g':`	235	`case 'g':`
236	`*s = '>';`	236	`*s = '>';`
237	`s++;`	237	`s++;`
238	`break;`	238	`break;`
239	`case 'L': /* $L = < (less-than sign) */`	239	`case 'L': /* $L = < (less-than sign) */`
240	`case 'l':`	240	`case 'l':`
241	`*s = '<';`	241	`*s = '<';`
242	`s++;`	242	`s++;`
243	`break;`	243	`break;`
244	`case 'B': /* $B = \| (pipe) */`	244	`case 'B': /* $B = \| (pipe) */`
245	`case 'b':`	245	`case 'b':`
246	`*s = '\|';`	246	`*s = '\|';`
247	`s++;`	247	`s++;`
248	`break;`	248	`break;`
249	`case 'H': /* $H = backspace (erases previous character) */`	249	`case 'H': /* $H = backspace (erases previous character) */`
250	`case 'h':`	250	`case 'h':`
251	`*s = '\b';`	251	`*s = '\b';`
252	`s++;`	252	`s++;`
253	`break;`	253	`break;`
254	`case 'E': /* $E = Escape code (ASCII 27) */`	254	`case 'E': /* $E = Escape code (ASCII 27) */`
255	`case 'e':`	255	`case 'e':`
256	`*s = 27;`	256	`*s = 27;`
257	`s++;`	257	`s++;`
258	`break;`	258	`break;`
259	`case '_': /* $_ = CR+LF */`	259	`case '_': /* $_ = CR+LF */`
260	`*s = '\r';`	260	`*s = '\r';`
261	`s++;`	261	`s++;`
262	`*s = '\n';`	262	`*s = '\n';`
263	`s++;`	263	`s++;`
264	`break;`	264	`break;`
265	`}`	265	`}`
266	`}`	266	`}`
267	`*s = '$';`	267	`*s = '$';`
268	`}`	268	`}`
269		269
270		270
271	`/* tries locating executable fname in path and fille res with result. returns 0 on success,`	271	`/* tries locating executable fname in path and fille res with result. returns 0 on success,`
272	`* -1 on failed match and -2 on failed match + "don't even try with other paths"`	272	`* -1 on failed match and -2 on failed match + "don't even try with other paths"`
273	`* format is filled the offset where extension starts in fname (-1 if not found) */`	273	`* format is filled the offset where extension starts in fname (-1 if not found) */`
274	`int lookup_cmd(char res, const char fname, const char path, const char *extptr) {`	274	`int lookup_cmd(char res, const char fname, const char path, const char *extptr) {`
275	`unsigned short lastbslash = 0xffff;`	275	`unsigned short lastbslash = 0xffff;`
276	`unsigned short i, len;`	276	`unsigned short i, len;`
277	`unsigned char explicitpath = 0;`	277	`unsigned char explicitpath = 0;`
278		278
279	`/* does the original fname had an explicit path prefix or explicit ext? */`	279	`/* does the original fname had an explicit path prefix or explicit ext? */`
280	`*extptr = NULL;`	280	`*extptr = NULL;`
281	`for (i = 0; fname[i] != 0; i++) {`	281	`for (i = 0; fname[i] != 0; i++) {`
282	`switch (fname[i]) {`	282	`switch (fname[i]) {`
283	`case ':':`	283	`case ':':`
284	`case '\\':`	284	`case '\\':`
285	`explicitpath = 1;`	285	`explicitpath = 1;`
286	`extptr = NULL; / extension is the last dot AFTER all path delimiters */`	286	`extptr = NULL; / extension is the last dot AFTER all path delimiters */`
287	`break;`	287	`break;`
288	`case '.':`	288	`case '.':`
289	`*extptr = fname + i + 1;`	289	`*extptr = fname + i + 1;`
290	`break;`	290	`break;`
291	`}`	291	`}`
292	`}`	292	`}`
293		293
294	`/* normalize filename */`	294	`/* normalize filename */`
295	`if (file_truename(fname, res) != 0) return(-2);`	295	`if (file_truename(fname, res) != 0) return(-2);`
296		296
297	`/* printf("truename: %s\r\n", res); */`	297	`/* printf("truename: %s\r\n", res); */`
298		298
299	`/* figure out where the command starts and if it has an explicit extension */`	299	`/* figure out where the command starts and if it has an explicit extension */`
300	`for (len = 0; res[len] != 0; len++) {`	300	`for (len = 0; res[len] != 0; len++) {`
301	`switch (res[len]) {`	301	`switch (res[len]) {`
302	`case '?': /* abort on any wildcard character */`	302	`case '?': /* abort on any wildcard character */`
303	`case '*':`	303	`case '*':`
304	`return(-2);`	304	`return(-2);`
305	`case '\\':`	305	`case '\\':`
306	`lastbslash = len;`	306	`lastbslash = len;`
307	`break;`	307	`break;`
308	`}`	308	`}`
309	`}`	309	`}`
310		310
311	`/* printf("lastbslash=%u\r\n", lastbslash); */`	311	`/* printf("lastbslash=%u\r\n", lastbslash); */`
312		312
313	`/* if no path prefix in fname (':' or backslash), then assemble path+filename */`	313	`/* if no path prefix in fname (':' or backslash), then assemble path+filename */`
314	`if (!explicitpath) {`	314	`if (!explicitpath) {`
315	`if (path != NULL) {`	315	`if (path != NULL) {`
316	`i = strlen(path);`	316	`i = strlen(path);`
317	`} else {`	317	`} else {`
318	`i = 0;`	318	`i = 0;`
319	`}`	319	`}`
320	`if ((i != 0) && (path[i - 1] != '\\')) i++; /* add a byte for inserting a bkslash after path */`	320	`if ((i != 0) && (path[i - 1] != '\\')) i++; /* add a byte for inserting a bkslash after path */`
321	`memmove(res + i, res + lastbslash + 1, len - lastbslash);`	321	`memmove(res + i, res + lastbslash + 1, len - lastbslash);`
322	`if (i != 0) {`	322	`if (i != 0) {`
323	`memmove(res, path, i);`	323	`memmove(res, path, i);`
324	`res[i - 1] = '\\';`	324	`res[i - 1] = '\\';`
325	`}`	325	`}`
326	`}`	326	`}`
327		327
328	`/* if no extension was initially provided, try matching COM, EXE, BAT */`	328	`/* if no extension was initially provided, try matching COM, EXE, BAT */`
329	`if (*extptr == NULL) {`	329	`if (*extptr == NULL) {`
330	`const char *ext[] = {".COM", ".EXE", ".BAT", NULL};`	330	`const char *ext[] = {".COM", ".EXE", ".BAT", NULL};`
331	`len = strlen(res);`	331	`len = strlen(res);`
332	`for (i = 0; ext[i] != NULL; i++) {`	332	`for (i = 0; ext[i] != NULL; i++) {`
333	`strcpy(res + len, ext[i]);`	333	`strcpy(res + len, ext[i]);`
334	`/* printf("? '%s'\r\n", res); */`	334	`/* printf("? '%s'\r\n", res); */`
335	`*extptr = ext[i] + 1;`	335	`*extptr = ext[i] + 1;`
336	`if (file_getattr(res) >= 0) return(0);`	336	`if (file_getattr(res) >= 0) return(0);`
337	`}`	337	`}`
338	`} else { /* try finding it as-is */`	338	`} else { /* try finding it as-is */`
339	`/* printf("? '%s'\r\n", res); */`	339	`/* printf("? '%s'\r\n", res); */`
340	`if (file_getattr(res) >= 0) return(0);`	340	`if (file_getattr(res) >= 0) return(0);`
341	`}`	341	`}`
342		342
343	`/* not found */`	343	`/* not found */`
344	`if (explicitpath) return(-2); /* don't bother trying other paths, the caller had its own path preset anyway */`	344	`if (explicitpath) return(-2); /* don't bother trying other paths, the caller had its own path preset anyway */`
345	`return(-1);`	345	`return(-1);`
346	`}`	346	`}`
347		347
348		348
349	`static void run_as_external(char buff, const char far cmdline, unsigned short envseg, struct rmod_props far *rmod) {`	349	`static void run_as_external(char buff, const char far cmdline, unsigned short envseg, struct rmod_props far *rmod) {`
350	`char const *argvlist = (void )(buff + 512);`	350	`char const *argvlist = (void )(buff + 512);`
351	`char *cmdfile = buff + 1024;`	351	`char *cmdfile = buff + 1024;`
352	`const char far *pathptr;`	352	`const char far *pathptr;`
353	`int lookup;`	353	`int lookup;`
354	`unsigned short i;`	354	`unsigned short i;`
355	`const char *ext;`	355	`const char *ext;`
356	`const char far *cmdtail;`	356	`const char far *cmdtail;`
357	`char far *rmod_execprog = MK_FP(rmod->rmodseg, RMOD_OFFSET_EXECPROG);`	357	`char far *rmod_execprog = MK_FP(rmod->rmodseg, RMOD_OFFSET_EXECPROG);`
358	`char far *rmod_cmdtail = MK_FP(rmod->rmodseg, 0x81);`	358	`char far *rmod_cmdtail = MK_FP(rmod->rmodseg, 0x81);`
359	`_Packed struct {`	359	`_Packed struct {`
360	`unsigned short envseg;`	360	`unsigned short envseg;`
361	`unsigned long cmdtail;`	361	`unsigned long cmdtail;`
362	`unsigned long fcb1;`	362	`unsigned long fcb1;`
363	`unsigned long fcb2;`	363	`unsigned long fcb2;`
364	`} far *ExecParam = MK_FP(rmod->rmodseg, RMOD_OFFSET_EXECPARAM);`	364	`} far *ExecParam = MK_FP(rmod->rmodseg, RMOD_OFFSET_EXECPARAM);`
365		365
366	`cmd_explode(buff + 2048, cmdline, argvlist);`	366	`cmd_explode(buff + 2048, cmdline, argvlist);`
367		367
368	`/* for (i = 0; argvlist[i] != NULL; i++) printf("arg #%d = '%s'\r\n", i, argvlist[i]); */`	368	`/* for (i = 0; argvlist[i] != NULL; i++) printf("arg #%d = '%s'\r\n", i, argvlist[i]); */`
369		369
370	`/* is this a command in curdir? */`	370	`/* is this a command in curdir? */`
371	`lookup = lookup_cmd(cmdfile, argvlist[0], NULL, &ext);`	371	`lookup = lookup_cmd(cmdfile, argvlist[0], NULL, &ext);`
372	`if (lookup == 0) {`	372	`if (lookup == 0) {`
373	`/* printf("FOUND LOCAL EXEC FILE: '%s'\r\n", cmdfile); */`	373	`/* printf("FOUND LOCAL EXEC FILE: '%s'\r\n", cmdfile); */`
374	`goto RUNCMDFILE;`	374	`goto RUNCMDFILE;`
375	`} else if (lookup == -2) {`	375	`} else if (lookup == -2) {`
376	`/* puts("NOT FOUND"); */`	376	`/* puts("NOT FOUND"); */`
377	`return;`	377	`return;`
378	`}`	378	`}`
379		379
380	`/* try matching something in PATH */`	380	`/* try matching something in PATH */`
381	`pathptr = env_lookup_val(envseg, "PATH");`	381	`pathptr = env_lookup_val(envseg, "PATH");`
382	`if (pathptr == NULL) return;`	382	`if (pathptr == NULL) return;`
383		383
384	`/* try each path in %PATH% */`	384	`/* try each path in %PATH% */`
385	`for (;;) {`	385	`for (;;) {`
386	`for (i = 0;; i++) {`	386	`for (i = 0;; i++) {`
387	`buff[i] = *pathptr;`	387	`buff[i] = *pathptr;`
388	`if ((buff[i] == 0) \|\| (buff[i] == ';')) break;`	388	`if ((buff[i] == 0) \|\| (buff[i] == ';')) break;`
389	`pathptr++;`	389	`pathptr++;`
390	`}`	390	`}`
391	`buff[i] = 0;`	391	`buff[i] = 0;`
392	`lookup = lookup_cmd(cmdfile, argvlist[0], buff, &ext);`	392	`lookup = lookup_cmd(cmdfile, argvlist[0], buff, &ext);`
393	`if (lookup == 0) break;`	393	`if (lookup == 0) break;`
394	`if (lookup == -2) return;`	394	`if (lookup == -2) return;`
395	`if (*pathptr == ';') {`	395	`if (*pathptr == ';') {`
396	`pathptr++;`	396	`pathptr++;`
397	`} else {`	397	`} else {`
398	`return;`	398	`return;`
399	`}`	399	`}`
400	`}`	400	`}`
401		401
402	`RUNCMDFILE:`	402	`RUNCMDFILE:`
403	`/* TODO run command through INT 0x21 */`	-
404	`/* TODO copy environment and append full exec path */`	-
405	`/* TODO special handling of batch files */`	403	`/* TODO special handling of batch files */`
406	`if ((ext != NULL) && (imatch(ext, "bat"))) {`	404	`if ((ext != NULL) && (imatch(ext, "bat"))) {`
407	`outputnl("batch processing not supported yet");`	405	`outputnl("batch processing not supported yet");`
408	`return;`	406	`return;`
409	`}`	407	`}`
410		408
411	`/* find cmdtail */`	409	`/* find cmdtail */`
412	`cmdtail = cmdline;`	410	`cmdtail = cmdline;`
413	`while (*cmdtail == ' ') cmdtail++;`	411	`while (*cmdtail == ' ') cmdtail++;`
414	`while ((cmdtail != ' ') && (cmdtail != '/') && (cmdtail != '+') && (cmdtail != 0)) {`	412	`while ((cmdtail != ' ') && (cmdtail != '/') && (cmdtail != '+') && (cmdtail != 0)) {`
415	`cmdtail++;`	413	`cmdtail++;`
416	`}`	414	`}`
417		415
418	`/* copy full filename to execute */`	416	`/* copy full filename to execute */`
419	`for (i = 0; cmdfile[i] != 0; i++) rmod_execprog[i] = cmdfile[i];`	417	`for (i = 0; cmdfile[i] != 0; i++) rmod_execprog[i] = cmdfile[i];`
420	`rmod_execprog[i] = 0;`	418	`rmod_execprog[i] = 0;`
421		419
422	`/* copy cmdtail to rmod's PSP and compute its len */`	420	`/* copy cmdtail to rmod's PSP and compute its len */`
423	`for (i = 0; cmdtail[i] != 0; i++) rmod_cmdtail[i] = cmdtail[i];`	421	`for (i = 0; cmdtail[i] != 0; i++) rmod_cmdtail[i] = cmdtail[i];`
424	`rmod_cmdtail[i] = '\r';`	422	`rmod_cmdtail[i] = '\r';`
425	`rmod_cmdtail[-1] = i;`	423	`rmod_cmdtail[-1] = i;`
426		424
427	`/* set up rmod to execute the command */`	425	`/* set up rmod to execute the command */`
428		426
429	`ExecParam->envseg = envseg;`	427	`ExecParam->envseg = envseg;`
430	`ExecParam->cmdtail = (unsigned long)MK_FP(rmod->rmodseg, 0x80); /* farptr, must be in PSP format (lenbyte args \r) */`	428	`ExecParam->cmdtail = (unsigned long)MK_FP(rmod->rmodseg, 0x80); /* farptr, must be in PSP format (lenbyte args \r) */`
431	`ExecParam->fcb1 = 0; /* TODO farptr */`	429	`ExecParam->fcb1 = 0; /* TODO farptr */`
432	`ExecParam->fcb2 = 0; /* TODO farptr */`	430	`ExecParam->fcb2 = 0; /* TODO farptr */`
433	`exit(0); /* let rmod do the job now */`	431	`exit(0); /* let rmod do the job now */`
434	`}`	432	`}`
435		433
436		434
437	`static void set_comspec_to_self(unsigned short envseg) {`	435	`static void set_comspec_to_self(unsigned short envseg) {`
438	`unsigned short psp_envseg = (void )(0x2c); /* pointer to my env segment field in the PSP */`	436	`unsigned short psp_envseg = (void )(0x2c); /* pointer to my env segment field in the PSP */`
439	`char far myenv = MK_FP(psp_envseg, 0);`	437	`char far myenv = MK_FP(psp_envseg, 0);`
440	`unsigned short varcount;`	438	`unsigned short varcount;`
441	`char buff[256] = "COMSPEC=";`	439	`char buff[256] = "COMSPEC=";`
442	`char *buffptr = buff + 8;`	440	`char *buffptr = buff + 8;`
443	`/* who am i? look into my own environment, at the end of it should be my EXEPATH string */`	441	`/* who am i? look into my own environment, at the end of it should be my EXEPATH string */`
444	`while (*myenv != 0) {`	442	`while (*myenv != 0) {`
445	`/* consume a NULL-terminated string */`	443	`/* consume a NULL-terminated string */`
446	`while (*myenv != 0) myenv++;`	444	`while (*myenv != 0) myenv++;`
447	`/* move to next string */`	445	`/* move to next string */`
448	`myenv++;`	446	`myenv++;`
449	`}`	447	`}`
450	`/* get next word, if 1 then EXEPATH follows */`	448	`/* get next word, if 1 then EXEPATH follows */`
451	`myenv++;`	449	`myenv++;`
452	`varcount = *myenv;`	450	`varcount = *myenv;`
453	`myenv++;`	451	`myenv++;`
454	`varcount \|= (*myenv << 8);`	452	`varcount \|= (*myenv << 8);`
455	`myenv++;`	453	`myenv++;`
456	`if (varcount != 1) return; /* NO EXEPATH FOUND */`	454	`if (varcount != 1) return; /* NO EXEPATH FOUND */`
457	`while (*myenv != 0) {`	455	`while (*myenv != 0) {`
458	`buffptr = myenv;`	456	`buffptr = myenv;`
459	`buffptr++;`	457	`buffptr++;`
460	`myenv++;`	458	`myenv++;`
461	`}`	459	`}`
462	`*buffptr = 0;`	460	`*buffptr = 0;`
463	`/* printf("EXEPATH: '%s'\r\n", buff); */`	461	`/* printf("EXEPATH: '%s'\r\n", buff); */`
464	`env_setvar(envseg, buff);`	462	`env_setvar(envseg, buff);`
465	`}`	463	`}`
466		464
467		465
468	`/* wait for user input */`	466	`/* wait for user input */`
469	`static void cmdline_getinput(unsigned short inpseg, unsigned short inpoff) {`	467	`static void cmdline_getinput(unsigned short inpseg, unsigned short inpoff) {`
470	`_asm {`	468	`_asm {`
471	`push ax`	469	`push ax`
472	`push bx`	470	`push bx`
473	`push cx`	471	`push cx`
474	`push dx`	472	`push dx`
475	`push ds`	473	`push ds`
476		474
477	`/* is DOSKEY support present? (INT 2Fh, AX=4800h, returns non-zero in AL if present) */`	475	`/* is DOSKEY support present? (INT 2Fh, AX=4800h, returns non-zero in AL if present) */`
478	`mov ax, 0x4800`	476	`mov ax, 0x4800`
479	`int 0x2f`	477	`int 0x2f`
480	`mov bl, al /* save doskey status in BL */`	478	`mov bl, al /* save doskey status in BL */`
481		479
482	`/* set up buffered input to inpseg:inpoff */`	480	`/* set up buffered input to inpseg:inpoff */`
483	`mov ax, inpseg`	481	`mov ax, inpseg`
484	`push ax`	482	`push ax`
485	`pop ds`	483	`pop ds`
486	`mov dx, inpoff`	484	`mov dx, inpoff`
487		485
488	`/* execute either DOS input or DOSKEY */`	486	`/* execute either DOS input or DOSKEY */`
489	`test bl, bl /* zf set if no DOSKEY present */`	487	`test bl, bl /* zf set if no DOSKEY present */`
490	`jnz DOSKEY`	488	`jnz DOSKEY`
491		489
492	`mov ah, 0x0a`	490	`mov ah, 0x0a`
493	`int 0x21`	491	`int 0x21`
494	`jmp short DONE`	492	`jmp short DONE`
495		493
496	`DOSKEY:`	494	`DOSKEY:`
497	`mov ax, 0x4810`	495	`mov ax, 0x4810`
498	`int 0x2f`	496	`int 0x2f`
499		497
500	`DONE:`	498	`DONE:`

Subversion Repositories SvarDOS

(root)/svarcom/trunk/command.c @ 1202 – Rev 464 → 465