2 * Redistribution and use in source and binary forms, with or without
3 * modification, are permitted provided that the following conditions
5 * 1. Redistributions of source code must retain the above copyright
6 * notice, this list of conditions and the following disclaimer.
7 * 2. Redistributions in binary form must reproduce the above copyright
8 * notice, this list of conditions and the following disclaimer in the
9 * documentation and/or other materials provided with the distribution.
14 * The meat of the simple parser.
17 #include <sys/cdefs.h>
18 __FBSDID("$FreeBSD$");
22 #include "bootstrap.h"
24 static void clean(void);
25 static int insert(int *argcp, char *buf);
26 static char *variable_lookup(char *name);
28 #define PARSE_BUFSIZE 1024 /* maximum size of one element */
29 #define MAXARGS 20 /* maximum number of elements */
30 static char *args[MAXARGS];
33 * parse: accept a string of input and "parse" it for backslash
34 * substitutions and environment variable expansions (${var}),
35 * returning an argc/argv style vector of whitespace separated
36 * arguments. Returns 0 on success, 1 on failure (ok, ok, so I
37 * wimped-out on the error codes! :).
39 * Note that the argv array returned must be freed by the caller, but
40 * we own the space allocated for arguments and will free that on next
41 * invocation. This allows argv consumers to modify the array if
44 * NB: environment variables that expand to more than one whitespace
45 * separated token will be returned as a single argv[] element, not
46 * split in turn. Expanded text is also immune to further backslash
47 * elimination or expansion since this is a one-pass, non-recursive
48 * parser. You didn't specify more than this so if you want more, ask
52 #define PARSE_FAIL(expr) \
54 printf("fail at line %d\n", __LINE__); \
61 /* Accept the usual delimiters for a variable, returning counterpart */
75 return (ch == '\'' || ch == '"');
79 parse(int *argc, char ***argv, char *str)
82 char *val, *p, *q, *copy = NULL;
84 char token, tmp, quote, *buf;
85 enum { STR, VAR, WHITE } state;
89 if (!str || (p = copy = backslash(str)) == NULL)
92 /* Initialize vector and state */
95 buf = (char *)malloc(PARSE_BUFSIZE);
98 /* And awaaaaaaaaay we go! */
102 if ((*p == '\\') && p[1]) {
104 PARSE_FAIL(i == (PARSE_BUFSIZE - 1));
106 } else if (isquote(*p)) {
107 quote = quote ? 0 : *p;
110 else if (isspace(*p) && !quote) {
114 PARSE_FAIL(insert(&ac, buf));
118 } else if (*p == '$') {
119 token = isdelim(*(p + 1));
126 PARSE_FAIL(i == (PARSE_BUFSIZE - 1));
140 PARSE_FAIL((q = index(p, token)) == NULL);
143 while (*q && !isspace(*q))
148 if ((val = variable_lookup(p)) != NULL) {
149 size_t len = strlen(val);
151 strncpy(buf + i, val, PARSE_BUFSIZE - (i + 1));
152 i += min(len, PARSE_BUFSIZE - 1);
154 *q = tmp; /* restore value */
155 p = q + (token ? 1 : 0);
160 /* If at end of token, add it */
161 if (i && state == STR) {
163 PARSE_FAIL(insert(&ac, buf));
167 *argv = (char **)malloc((sizeof(char *) * ac + 1));
168 bcopy(args, *argv, sizeof(char *) * ac + 1);
176 /* Clean vector space */
182 for (i = 0; i < MAXARGS; i++) {
183 if (args[i] != NULL) {
191 insert(int *argcp, char *buf)
193 if (*argcp >= MAXARGS)
195 args[(*argcp)++] = strdup(buf);
200 variable_lookup(char *name)
202 /* XXX search "special variable" space first? */
203 return (char *)getenv(name);