about summary refs log tree commit diff
path: root/src/misc/wordexp.c
blob: 171f27027f6670bd735559948e1c1aef098cb167 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
#include <wordexp.h>
#include <unistd.h>
#include <stdio.h>
#include <string.h>
#include <limits.h>
#include <stdint.h>
#include <stdlib.h>
#include <sys/wait.h>
#include <signal.h>

static char *getword(FILE *f)
{
	char *s = 0;
	return getdelim(&s, (size_t [1]){0}, 0, f) < 0 ? 0 : s;
}

int wordexp(const char *s, wordexp_t *we, int flags)
{
	size_t i, l;
	int sq=0, dq=0;
	size_t np=0;
	char *w, **tmp;
	char *redir = (flags & WRDE_SHOWERR) ? "" : "2>/dev/null";
	int err = 0, status;
	FILE *f;
	size_t wc = 0;
	char **wv = 0;
	int p[2];
	pid_t pid;

	if (flags & WRDE_REUSE) wordfree(we);

	if (flags & WRDE_NOCMD) for (i=0; s[i]; i++) switch (s[i]) {
	case '\\':
		if (!sq) i++;
		break;
	case '\'':
		if (!dq) sq^=1;
		break;
	case '"':
		if (!sq) dq^=1;
		break;
	case '(':
		if (np) {
			np++;
			break;
		}
	case ')':
		if (np) {
			np--;
			break;
		}
	case '\n':
	case '|':
	case '&':
	case ';':
	case '<':
	case '>':
	case '{':
	case '}':
		if (!(sq|dq|np)) return WRDE_BADCHAR;
		break;
	case '$':
		if (s[i+1]=='(' && s[i+2]=='(') {
			i += 2;
			np += 2;
			break;
		} else if (s[i+1] != '(') break;
	case '`':
		if (sq) break;
		return WRDE_CMDSUB;
	}

	if (flags & WRDE_APPEND) {
		wc = we->we_wordc;
		wv = we->we_wordv;
	}

	i = wc;
	if (flags & WRDE_DOOFFS) {
		if (we->we_offs > SIZE_MAX/sizeof(void *)/4)
			return WRDE_NOSPACE;
		i += we->we_offs;
	}

	pipe(p);
	pid = fork();
	if (!pid) {
		dup2(p[1], 1);
		close(p[0]);
		close(p[1]);
		execl("/bin/sh", "sh", "-c",
			"eval \"printf %s\\\\\\\\0 $1 $2\"",
			"sh", s, redir, (char *)0);
		_exit(1);
	}
	close(p[1]);
	
	f = fdopen(p[0], "r");
	if (!f) {
		close(p[0]);
		kill(pid, SIGKILL);
		waitpid(pid, &status, 0);
		return WRDE_NOSPACE;
	}

	l = wv ? i+1 : 0;

	while ((w = getword(f))) {
		if (i+1 >= l) {
			l += l/2+10;
			tmp = realloc(wv, l*sizeof(char *));
			if (!tmp) break;
			wv = tmp;
		}
		wv[i++] = w;
		wv[i] = 0;
	}
	if (!feof(f)) err = WRDE_NOSPACE;

	fclose(f);
	waitpid(pid, &status, 0);
	if (WEXITSTATUS(status)) {
		if (!(flags & WRDE_APPEND)) {
			free(wv);
			return WRDE_SYNTAX;
		} else if (wv==we->we_wordv) {
			return WRDE_SYNTAX;
		}
	}

	we->we_wordv = wv;
	we->we_wordc = i - we->we_offs;
	return err;
}

void wordfree(wordexp_t *we)
{
	size_t i;
	if (!we->we_wordv) return;
	for (i=0; i<we->we_wordc; i++) free(we->we_wordv[we->we_offs+i]);
	free(we->we_wordv);
	we->we_wordv = 0;
	we->we_wordc = 0;
}