Subversion Repositories SvarDOS

Rev

Rev 365 | Rev 371 | Go to most recent revision | Details | Compare with Previous | Last modification | View Log | RSS feed

Rev Author Line No. Line
352 mateuszvis 1
/* entry point for internal commands
2
 * matches internal commands and executes them
353 mateuszvis 3
 * returns -1 or exit code if processed
4
 * returns -2 if command unrecognized */
352 mateuszvis 5
 
6
#include <i86.h>
7
#include <stdio.h>
364 mateuszvis 8
#include <stdlib.h>
352 mateuszvis 9
 
363 mateuszvis 10
#include "doserr.h"
352 mateuszvis 11
#include "helpers.h"
12
 
364 mateuszvis 13
struct cmd_funcparam {
14
  int argc;
15
  const char *argv[256];
16
  unsigned short env_seg;
17
  const char far *cmdline;
18
};
19
 
363 mateuszvis 20
#include "cmd/cd.c"
368 mateuszvis 21
#include "cmd/dir.c"
364 mateuszvis 22
#include "cmd/exit.c"
352 mateuszvis 23
#include "cmd/set.c"
24
 
25
#include "cmd.h"
26
 
27
 
364 mateuszvis 28
struct CMD_ID {
29
  const char *cmd;
30
  int (*func_ptr)(const struct cmd_funcparam *); /* pointer to handling function */
31
};
352 mateuszvis 32
 
364 mateuszvis 33
const struct CMD_ID INTERNAL_CMDS[] = {
34
  {"CD",      cmd_cd},
35
  {"CHDIR",   cmd_cd},
368 mateuszvis 36
  {"DIR",     cmd_dir},
364 mateuszvis 37
  {"EXIT",    cmd_exit},
38
  {"SET",     cmd_set},
39
  {NULL,      NULL}
40
};
41
 
42
 
43
/* NULL if cmdline is not matching an internal command, otherwise returns a
44
 * pointer to a CMD_ID struct */
45
static const struct CMD_ID *cmd_match(const char far *cmdline, unsigned short *argoffset) {
46
  unsigned short i;
47
  char buff[10];
48
 
49
  /* copy command to buffer, until space, NULL, tab, return, dot, slash or backslash */
50
  for (i = 0; i < 9; i++) {
51
    if (cmdline[i] == ' ') break;
52
    if (cmdline[i] == 0) break;
53
    if (cmdline[i] == '\t') break;
54
    if (cmdline[i] == '\r') break;
55
    if (cmdline[i] == '.') break;
56
    if (cmdline[i] == '/') break;
57
    if (cmdline[i] == '\\') break;
58
    buff[i] = cmdline[i];
59
  }
60
  buff[i] = 0;
61
 
62
  /* advance to nearest non-space to find where arguments start */
63
  while (cmdline[i] == ' ') i++;
64
  *argoffset = i;
65
 
66
  /* try matching an internal command */
67
  for (i = 0; INTERNAL_CMDS[i].cmd != NULL; i++) {
68
    /*printf("imatch(%s,%s)\r\n", buff, INTERNAL_CMDS[i].cmd); */
69
    if (imatch(buff, INTERNAL_CMDS[i].cmd)) {
70
      /*printf("match cmd i=%u (buff=%s)\r\n", i, buff);*/
71
      return(&(INTERNAL_CMDS[i]));
72
    }
73
  }
74
 
75
  return(NULL); /* command is not recognized as internal */
352 mateuszvis 76
}
364 mateuszvis 77
 
78
 
79
/* explodes a command into an array of arguments where last arg is NULL
80
 * returns number of args */
81
unsigned short cmd_explode(char *buff, const char far *s, char const **argvlist) {
82
  int si = 0, argc = 0, i = 0;
83
  for (;;) {
84
    /* skip to next non-space character */
85
    while (s[si] == ' ') si++;
86
    /* end of string? */
87
    if (s[si] == 0) break;
88
    /* set argv ptr */
89
    argvlist[argc++] = buff + i;
90
    /* find next space while copying arg to local buffer */
91
    do {
92
      buff[i++] = s[si++];
93
    } while (s[si] != ' ' && s[si] != 0 && s[si] != '/');
94
    buff[i++] = 0;
95
    /* is this end of string? */
96
    if (s[si] == 0) break;
97
  }
98
  argvlist[argc] = NULL;
99
  return(argc);
100
}
101
 
102
 
103
int cmd_process(unsigned short env_seg, const char far *cmdline) {
104
  const struct CMD_ID *cmdptr;
105
  struct cmd_funcparam p;
106
  unsigned short argoffset;
107
  char cmdbuff[256];
108
 
365 mateuszvis 109
  /* special case: is this a drive change? (like "E:") */
110
  if ((cmdline[0] != 0) && (cmdline[1] == ':') && ((cmdline[2] == ' ') || (cmdline[2] == 0))) {
111
    if (((cmdline[0] >= 'a') && (cmdline[0] <= 'z')) || ((cmdline[0] >= 'A') && (cmdline[0] <= 'Z'))) {
112
      unsigned char drive = cmdline[0];
113
      unsigned char curdrive = 0;
114
      if (drive >= 'a') {
115
        drive -= 'a';
116
      } else {
117
        drive -= 'A';
118
      }
119
      _asm {
120
        push ax
121
        push dx
122
        mov ah, 0x0e     /* DOS 1+ - SELECT DEFAULT DRIVE */
123
        mov dl, drive    /* DL = new default drive (00h = A:, 01h = B:, etc) */
124
        int 0x21
125
        mov ah, 0x19     /* DOS 1+ - GET CURRENT DRIVE */
126
        int 0x21
127
        mov curdrive, al /* cur drive (0=A, 1=B, etc) */
128
        pop dx
129
        pop ax
130
      }
131
      if (curdrive != drive) puts(doserr(0x0f));
132
      return(-1);
133
    }
134
  }
135
 
136
  /* try matching an internal command */
364 mateuszvis 137
  cmdptr = cmd_match(cmdline, &argoffset);
138
  if (cmdptr == NULL) return(-2); /* command is not recognized as internal */
139
 
140
  /* printf("recognized internal command: '%s', tail of command at offset %u\r\n", cmdptr->cmd, argoffset); */
141
 
142
  /* prepare function parameters and feed it to the cmd handling function */
143
  p.argc = cmd_explode(cmdbuff, cmdline + argoffset, p.argv);
144
  p.env_seg = env_seg;
145
  p.cmdline = cmdline;
146
 
147
  return((cmdptr->func_ptr)(&p));
148
}