cmd-string.c

   1 /* $Id: cmd-string.c,v 1.13 2009-02-16 19:29:17 nicm Exp $ */
   2
   3 /*
   4  * Copyright (c) 2008 Nicholas Marriott <nicm@users.sourceforge.net>
   5  *
   6  * Permission to use, copy, modify, and distribute this software for any
   7  * purpose with or without fee is hereby granted, provided that the above
   8  * copyright notice and this permission notice appear in all copies.
   9  *
  10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  14  * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
  15  * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
  16  * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  17  */
  18
  19 #include <sys/types.h>
  20
  21 #include <errno.h>
  22 #include <stdio.h>
  23 #include <string.h>
  24 #include <stdlib.h>
  25
  26 #include "tmux.h"
  27
  28 /*
  29  * Parse a command from a string.
  30  */
  31
  32 int     cmd_string_getc(const char *, size_t *);
  33 void    cmd_string_ungetc(const char *, size_t *);
  34 char   *cmd_string_string(const char *, size_t *, char, int);
  35 char   *cmd_string_variable(const char *, size_t *);
  36
  37 int
  38 cmd_string_getc(const char *s, size_t *p)
  39 {
  40         if (s[*p] == '\0')
  41                 return (EOF);
  42         return (s[(*p)++]);
  43 }
  44
  45 void
  46 cmd_string_ungetc(unused const char *s, size_t *p)
  47 {
  48         (*p)--;
  49 }
  50
  51 /*
  52  * Parse command string. Returns -1 on error. If returning -1, cause is error
  53  * string, or NULL for empty command.
  54  */
  55 int
  56 cmd_string_parse(const char *s, struct cmd_list **cmdlist, char **cause)
  57 {
  58         size_t          p;
  59         int             ch, argc, rval, have_arg;
  60         char          **argv, *buf, *t, *u;
  61         size_t          len;
  62
  63         if ((t = strchr(s, ' ')) == NULL && (t = strchr(s, '\t')) == NULL)
  64                 t = strchr(s, '\0');
  65         if ((u = strchr(s, '=')) != NULL && u < t) {
  66                 if (putenv(s) != 0) {
  67                         xasprintf(cause, "assignment failed: %s", s);
  68                         return (-1);
  69                 }
  70                 *cmdlist = NULL;
  71                 return (0);
  72         }
  73
  74         argv = NULL;
  75         argc = 0;
  76
  77         buf = NULL;
  78         len = 0;
  79
  80         have_arg = 0;
  81
  82         *cause = NULL;
  83
  84         *cmdlist = NULL;
  85         rval = -1;
  86
  87         p = 0;
  88         for (;;) {
  89                 ch = cmd_string_getc(s, &p);
  90                 switch (ch) {
  91                 case '\'':
  92                         if ((t = cmd_string_string(s, &p, '\'', 0)) == NULL)
  93                                 goto error;
  94                         buf = xrealloc(buf, 1, len + strlen(t) + 1);
  95                         strlcpy(buf + len, t, strlen(t) + 1);
  96                         len += strlen(t);
  97                         xfree(t);
  98
  99                         have_arg = 1;
 100                         break;
 101                 case '"':
 102                         if ((t = cmd_string_string(s, &p, '"', 1)) == NULL)
 103                                 goto error;
 104                         buf = xrealloc(buf, 1, len + strlen(t) + 1);
 105                         strlcpy(buf + len, t, strlen(t) + 1);
 106                         len += strlen(t);
 107                         xfree(t);
 108
 109                         have_arg = 1;
 110                         break;
 111                 case '$':
 112                         if ((t = cmd_string_variable(s, &p)) == NULL)
 113                                 goto error;
 114                         buf = xrealloc(buf, 1, len + strlen(t) + 1);
 115                         strlcpy(buf + len, t, strlen(t) + 1);
 116                         len += strlen(t);
 117
 118                         have_arg = 1;
 119                         break;
 120                 case '#':
 121                         /* Comment: discard rest of line. */
 122                         while ((ch = cmd_string_getc(s, &p)) != EOF)
 123                                 ;
 124                         /* FALLTHROUGH */
 125                 case EOF:
 126                 case ' ':
 127                 case '\t':
 128                         if (have_arg) {
 129                                 buf = xrealloc(buf, 1, len + 1);
 130                                 buf[len] = '\0';
 131
 132                                 argv = xrealloc(argv, argc + 1, sizeof *argv);
 133                                 argv[argc++] = buf;
 134
 135                                 buf = NULL;
 136                                 len = 0;
 137
 138                                 have_arg = 0;
 139                         }
 140
 141                         if (ch != EOF)
 142                                 break;
 143                         if (argc == 0)
 144                                 goto out;
 145
 146                         *cmdlist = cmd_list_parse(argc, argv, cause);
 147                         if (*cmdlist == NULL)
 148                                 goto out;
 149
 150                         do
 151                                 xfree(argv[argc - 1]);
 152                         while (--argc > 0);
 153
 154                         rval = 0;
 155                         goto out;
 156                 default:
 157                         if (len >= SIZE_MAX - 2)
 158                                 goto error;
 159
 160                         buf = xrealloc(buf, 1, len + 1);
 161                         buf[len++] = ch;
 162
 163                         have_arg = 1;
 164                         break;
 165                 }
 166         }
 167
 168 error:
 169         xasprintf(cause, "invalid or unknown command: %s", s);
 170
 171 out:
 172         if (buf != NULL)
 173                 xfree(buf);
 174
 175         while (--argc >= 0)
 176                 xfree(argv[argc]);
 177         if (argv != NULL)
 178                 xfree(argv);
 179
 180         return (rval);
 181 }
 182
 183 char *
 184 cmd_string_string(const char *s, size_t *p, char endch, int esc)
 185 {
 186         int     ch;
 187         char   *buf, *t;
 188         size_t  len;
 189
 190         buf = NULL;
 191         len = 0;
 192
 193         while ((ch = cmd_string_getc(s, p)) != endch) {
 194                 switch (ch) {
 195                 case EOF:
 196                         goto error;
 197                 case '\\':
 198                         if (!esc)
 199                                 break;
 200                         switch (ch = cmd_string_getc(s, p)) {
 201                         case EOF:
 202                                 goto error;
 203                         case 'r':
 204                                 ch = '\r';
 205                                 break;
 206                         case 'n':
 207                                 ch = '\n';
 208                                 break;
 209                         case 't':
 210                                 ch = '\t';
 211                                 break;
 212                         }
 213                         break;
 214                 case '$':
 215                         if (!esc)
 216                                 break;
 217                         if ((t = cmd_string_variable(s, p)) == NULL)
 218                                 goto error;
 219                         buf = xrealloc(buf, 1, len + strlen(t) + 1);
 220                         strlcpy(buf + len, t, strlen(t) + 1);
 221                         len += strlen(t);
 222                         continue;
 223                 }
 224
 225                 if (len >= SIZE_MAX - 2)
 226                         goto error;
 227                 buf = xrealloc(buf, 1, len + 1);
 228                 buf[len++] = ch;
 229         }
 230
 231         buf = xrealloc(buf, 1, len + 1);
 232         buf[len] = '\0';
 233         return (buf);
 234
 235 error:
 236         if (buf != NULL)
 237                 xfree(buf);
 238         return (NULL);
 239 }
 240
 241 char *
 242 cmd_string_variable(const char *s, size_t *p)
 243 {
 244         int     ch, fch;
 245         char   *buf, *t;
 246         size_t  len;
 247
 248 #define cmd_string_first(ch) ((ch) == '_' || \
 249         ((ch) >= 'a' && (ch) <= 'z') || ((ch) >= 'A' && (ch) <= 'Z'))
 250 #define cmd_string_other(ch) ((ch) == '_' || \
 251         ((ch) >= 'a' && (ch) <= 'z') || ((ch) >= 'A' && (ch) <= 'Z') || \
 252         ((ch) >= '0' && (ch) <= '9'))
 253
 254         buf = NULL;
 255         len = 0;
 256
 257         fch = EOF;
 258         switch (ch = cmd_string_getc(s, p)) {
 259         case EOF:
 260                 goto error;
 261         case '{':
 262                 fch = '{';
 263
 264                 ch = cmd_string_getc(s, p);
 265                 if (!cmd_string_first(ch))
 266                         goto error;
 267                 /* FALLTHROUGH */
 268         default:
 269                 if (!cmd_string_first(ch)) {
 270                         xasprintf(&t, "$%c", ch);
 271                         return (t);
 272                 }
 273
 274                 buf = xrealloc(buf, 1, len + 1);
 275                 buf[len++] = ch;
 276
 277                 for(;;) {
 278                         ch = cmd_string_getc(s, p);
 279                         if (ch == EOF || !cmd_string_other(ch))
 280                                 break;
 281                         else {
 282                                 if (len >= SIZE_MAX - 3)
 283                                         goto error;
 284                                 buf = xrealloc(buf, 1, len + 1);
 285                                 buf[len++] = ch;
 286                         }
 287                 }
 288         }
 289
 290         if (fch == '{' && ch != '}')
 291                 goto error;
 292         if (ch != EOF && fch != '{')
 293                 cmd_string_ungetc(s, p); /* ch */
 294
 295         buf = xrealloc(buf, 1, len + 1);
 296         buf[len] = '\0';
 297
 298         if ((t = getenv(buf)) == NULL) {
 299                 xfree(buf);
 300                 return (xstrdup(""));
 301         }
 302         xfree(buf);
 303         return (xstrdup(t));
 304
 305 error:
 306         if (buf != NULL)
 307                 xfree(buf);
 308         return (NULL);
 309 }