console_args.c

   1 /**
   2  * License - GPL
   3  *
   4  * Command-line splitter function.
   5  * Lon Hohberger <lon@metamorphism.com>
   6  */
   7 #include <stdio.h>
   8 #include <string.h>
   9 #include <errno.h>
  10 #include <malloc.h>
  11
  12 typedef enum _command_state {
  13         STATE_QUOTE = 0x1,
  14         STATE_LITERAL = 0x2,
  15         STATE_COPY = 0x4
  16 } command_state_t;
  17
  18
  19 /**
  20  * Break up a command string into argv values.  Rudimentary.
  21  * Destroys the value of cmdline (inserts 0s in order to keep argv
  22  * pointers 0-terminated in typical C-style)
  23  */
  24 int
  25 command_split(char *cmdline, int *argc, char **argv, int max)
  26 {
  27         char *cmd_copy = NULL;
  28         command_state_t state = 0;
  29         int offset = 0, copy_offset = 0, ret = 1;
  30
  31         if (max <= 0 || argv == NULL || argc == NULL) {
  32                 errno = EINVAL;
  33                 return -1;
  34         }
  35
  36         cmd_copy = strdup(cmdline);
  37         if (!cmd_copy)
  38                 return -1;
  39
  40         memset(cmdline, 0, strlen(cmdline)+1);
  41         *argc = 0;
  42
  43         while (cmd_copy[copy_offset]) {
  44                 switch(cmd_copy[copy_offset]) {
  45                 case ' ':
  46                 case '\t':
  47                 case '\r':
  48                 case '\n':
  49                         if (state & (STATE_LITERAL | STATE_QUOTE))
  50                                 break;
  51                         if (state & STATE_COPY) {
  52                                 state &= ~STATE_COPY;
  53                                 cmdline[offset++] = 0;
  54                                 continue;
  55                         }
  56                         if (!state) {
  57                                 copy_offset++;
  58                                 continue;
  59                         }
  60                         break;
  61                 case '\\':
  62                         if (state & STATE_LITERAL)
  63                                 break;
  64                         state |= STATE_LITERAL;
  65                         ++copy_offset;
  66                         continue;
  67
  68                 case '\"':
  69                         if (state & STATE_LITERAL)
  70                                 break;
  71                         if (state & STATE_QUOTE) {
  72                                 state &= ~STATE_QUOTE;
  73                         } else {
  74                                 state |= STATE_QUOTE;
  75                         }
  76                         ++copy_offset;
  77                         continue;
  78                 }
  79
  80                 if (!(state & STATE_COPY)) {
  81                         if (*argc >= max)
  82                                 goto out;
  83                         state |= STATE_COPY;
  84                         argv[(*argc)++] = &cmdline[offset];
  85                 }
  86
  87                 state &= ~STATE_LITERAL;
  88
  89                 cmdline[offset] = cmd_copy[copy_offset];
  90                 ++offset;
  91                 ++copy_offset;
  92         }
  93         ret = 0;
  94
  95 out:
  96         if (cmd_copy)
  97                 free(cmd_copy);
  98         return ret;
  99 }
 100