Subversion Repositories SvarDOS

/* This file is part of the SvarCOM project and is published under the terms

 * of the MIT license.

 *

 * Copyright (C) 2021-2022 Mateusz Viste

 *

 * Permission is hereby granted, free of charge, to any person obtaining a

 * copy of this software and associated documentation files (the "Software"),

 * to deal in the Software without restriction, including without limitation

 * the rights to use, copy, modify, merge, publish, distribute, sublicense,

 * and/or sell copies of the Software, and to permit persons to whom the

 * Software is furnished to do so, subject to the following conditions:

 *

 * The above copyright notice and this permission notice shall be included in

 * all copies or substantial portions of the Software.

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE

 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING

 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER

 * DEALINGS IN THE SOFTWARE.

 */

/* entry point for internal commands

 * matches internal commands and executes them

 * returns -1 or exit code if processed

 * returns -2 if command unrecognized

 */

#include <i86.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include "env.h"

#include "helpers.h"

#include "redir.h"

#include "rmodinit.h"

#include "sayonara.h"

#include "cmd.h"

struct cmd_funcparam {

  int argc;                 /* number of arguments */

  const char *argv[128];    /* pointers to each argument */

  char argvbuf[256];        /* buffer that hold data pointed out by argv[] */

  unsigned short env_seg;   /* segment of environment block */

  struct rmod_props far *rmod; /* rmod settings */

  unsigned short argoffset; /* offset of cmdline where first argument starts */

  const char *cmdline;      /* original cmdline (terminated by a NULL) */

  unsigned short BUFFERSZ;  /* avail space in BUFFER */

  char BUFFER[1];           /* a buffer for whatever is needed (must be last) */

};

/* scans argv for the presence of a "/?" parameter. returns 1 if found, 0 otherwise */

static int cmd_ishlp(const struct cmd_funcparam *p) {

  int i;

  for (i = 0; i < p->argc; i++) {

    if ((p->argv[i][0] == '/') && (p->argv[i][1] == '?')) return(1);

  }

  return(0);

}

#include "cmd/_notimpl.c"

#include "cmd/break.c"

#include "cmd/cd.c"

#include "cmd/chcp.c"

#include "cmd/cls.c"

#include "cmd/copy.c"

#include "cmd/date.c"

#include "cmd/del.c"

#include "cmd/if.c"

#include "cmd/vol.c"     /* must be included before dir.c due to dependency */

#include "cmd/dir.c"

#include "cmd/echo.c"

#include "cmd/exit.c"

#include "cmd/ln.c"

#include "cmd/mkdir.c"

#include "cmd/path.c"

#include "cmd/pause.c"

#include "cmd/prompt.c"

#include "cmd/rem.c"

#include "cmd/rename.c"

#include "cmd/rmdir.c"

#include "cmd/set.c"

#include "cmd/shift.c"

#include "cmd/time.c"

#include "cmd/type.c"

#include "cmd/ver.c"

#include "cmd/verify.c"

struct CMD_ID {

  const char *cmd;

  enum cmd_result (*func_ptr)(struct cmd_funcparam *); /* pointer to handling function */

};

const struct CMD_ID INTERNAL_CMDS[] = {

  {"BREAK",   cmd_break},

  {"CD",      cmd_cd},

  {"CHCP",    cmd_chcp},

  {"CHDIR",   cmd_cd},

  {"CLS",     cmd_cls},

  {"COPY",    cmd_copy},

  {"CTTY",    cmd_notimpl},

  {"DATE",    cmd_date},

  {"DEL",     cmd_del},

  {"DIR",     cmd_dir},

  {"ECHO",    cmd_echo},

  {"ERASE",   cmd_del},

  {"EXIT",    cmd_exit},

  {"IF",      cmd_if},

  {"LH",      cmd_notimpl},

  {"LN",      cmd_ln},

  {"LOADHIGH",cmd_notimpl},

  {"MD",      cmd_mkdir},

  {"MKDIR",   cmd_mkdir},

  {"PAUSE",   cmd_pause},

  {"PATH",    cmd_path},

  {"PROMPT",  cmd_prompt},

  {"RD",      cmd_rmdir},

  {"REM",     cmd_rem},

  {"REN",     cmd_rename},

  {"RENAME",  cmd_rename},

  {"RMDIR",   cmd_rmdir},

  {"SET",     cmd_set},

  {"SHIFT",   cmd_shift},

  {"TIME",    cmd_time},

  {"TYPE",    cmd_type},

  {"VER",     cmd_ver},

  {"VERIFY",  cmd_verify},

  {"VOL",     cmd_vol},

  {NULL,      NULL}

};

/* NULL if cmdline is not matching an internal command, otherwise returns a

 * pointer to a CMD_ID struct */

static const struct CMD_ID *cmd_match(const char *cmdline, unsigned short *argoffset) {

  unsigned short i;

  char buff[10];

  /* copy command to buffer, until space, NULL, tab, return, dot, slash or backslash */

  for (i = 0; i < 9; i++) {

    if (cmdline[i] == ' ') break;

    if (cmdline[i] == 0) break;

    if (cmdline[i] == '\t') break;

    if (cmdline[i] == '\r') break;

    if (cmdline[i] == '.') break;

    if (cmdline[i] == '/') break;

    if (cmdline[i] == '\\') break;

    buff[i] = cmdline[i];

  }

  buff[i] = 0;

  /* advance to nearest non-space to find where arguments start */

  while (cmdline[i] == ' ') i++;

  *argoffset = i;

  /* try matching an internal command */

  for (i = 0; INTERNAL_CMDS[i].cmd != NULL; i++) {

    /*printf("imatch(%s,%s)\r\n", buff, INTERNAL_CMDS[i].cmd); */

    if (imatch(buff, INTERNAL_CMDS[i].cmd)) {

      /*printf("match cmd i=%u (buff=%s)\r\n", i, buff);*/

      return(&(INTERNAL_CMDS[i]));

    }

  }

  return(NULL); /* command is not recognized as internal */

}

/* explodes a command into an array of arguments where last arg is NULL.

 * if argvlist is not NULL, it will be filled with pointers that point to buff

 * locations. buff is filled with all the arguments, each argument being

 * zero-separated. buff is terminated with an empty argument to mark the end

 * of arguments.

 * returns number of args */

unsigned short cmd_explode(char *buff, const char far *s, char const **argvlist) {

  int si = 0, argc = 0, i = 0;

  for (;;) {

    /* skip to next non-space character */

    while (s[si] == ' ') si++;

    /* end of string? */

    if (s[si] == 0) break;

    /* set argv ptr */

    if (argvlist) argvlist[argc] = buff + i;

    argc++;

    /* find next arg delimiter (spc, null, slash or plus) while copying arg to local buffer */

    do {

      buff[i++] = s[si++];

    } while (s[si] != ' ' && s[si] != 0 && s[si] != '/' && s[si] != '+');

    buff[i++] = 0;

    /* is this end of string? */

    if (s[si] == 0) break;

  }

  buff[i] = 0; /* terminate with one extra zero to tell "this is the end of list" */

  if (argvlist) argvlist[argc] = NULL;

  return(argc);

}

enum cmd_result cmd_process(struct rmod_props far *rmod, unsigned short env_seg, const char *cmdline, void *BUFFER, unsigned short BUFFERSZ, const struct redir_data *redir) {

  const struct CMD_ID *cmdptr;

  unsigned short argoffset;

  enum cmd_result cmdres;

  struct cmd_funcparam *p = (void *)BUFFER;

  p->BUFFERSZ = BUFFERSZ - sizeof(*p);

  /* special case: is this a drive change? (like "E:") */

  if ((cmdline[0] != 0) && (cmdline[1] == ':') && ((cmdline[2] == ' ') || (cmdline[2] == 0))) {

    if (((cmdline[0] >= 'a') && (cmdline[0] <= 'z')) || ((cmdline[0] >= 'A') && (cmdline[0] <= 'Z'))) {

      unsigned char drive = cmdline[0];

      unsigned char curdrive = 0;

      if (drive >= 'a') {

        drive -= 'a';

      } else {

        drive -= 'A';

      }

      _asm {

        push ax

        push dx

        mov ah, 0x0e     /* DOS 1+ - SELECT DEFAULT DRIVE */

        mov dl, drive    /* DL = new default drive (00h = A:, 01h = B:, etc) */

        int 0x21

        mov ah, 0x19     /* DOS 1+ - GET CURRENT DRIVE */

        int 0x21

        mov curdrive, al /* cur drive (0=A, 1=B, etc) */

        pop dx

        pop ax

      }

      if (curdrive == drive) return(CMD_OK);

      nls_outputnl_doserr(0x0f);

      return(CMD_FAIL);

    }

  }

  /* try matching an internal command */

  cmdptr = cmd_match(cmdline, &argoffset);

  if (cmdptr == NULL) return(CMD_NOTFOUND); /* command is not recognized as internal */

  /* printf("recognized internal command: '%s', tail of command at offset %u\r\n", cmdptr->cmd, argoffset); */

  /* apply redirections (if any) */

  if (redir_apply(redir) != 0) return(CMD_FAIL);

  /* prepare function parameters and feed it to the cmd handling function */

  p->argc = cmd_explode(p->argvbuf, cmdline + argoffset, p->argv);

  p->env_seg = env_seg;

  p->rmod = rmod;

  p->argoffset = argoffset;

  p->cmdline = cmdline;

  cmdres = (cmdptr->func_ptr)(p);

  /* cancel redirections */

  redir_revert();

  return(cmdres);

}