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