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
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
|
#include <linux/compiler.h>
#include <linux/string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include "subcmd-util.h"
#include "exec-cmd.h"
#include "subcmd-config.h"
#define MAX_ARGS 32
#define PATH_MAX 4096
static const char *argv_exec_path;
static const char *argv0_path;
void exec_cmd_init(const char *exec_name, const char *prefix,
const char *exec_path, const char *exec_path_env)
{
subcmd_config.exec_name = exec_name;
subcmd_config.prefix = prefix;
subcmd_config.exec_path = exec_path;
subcmd_config.exec_path_env = exec_path_env;
}
#define is_dir_sep(c) ((c) == '/')
static int is_absolute_path(const char *path)
{
return path[0] == '/';
}
static const char *get_pwd_cwd(void)
{
static char cwd[PATH_MAX + 1];
char *pwd;
struct stat cwd_stat, pwd_stat;
if (getcwd(cwd, PATH_MAX) == NULL)
return NULL;
pwd = getenv("PWD");
if (pwd && strcmp(pwd, cwd)) {
stat(cwd, &cwd_stat);
if (!stat(pwd, &pwd_stat) &&
pwd_stat.st_dev == cwd_stat.st_dev &&
pwd_stat.st_ino == cwd_stat.st_ino) {
strlcpy(cwd, pwd, PATH_MAX);
}
}
return cwd;
}
static const char *make_nonrelative_path(const char *path)
{
static char buf[PATH_MAX + 1];
if (is_absolute_path(path)) {
if (strlcpy(buf, path, PATH_MAX) >= PATH_MAX)
die("Too long path: %.*s", 60, path);
} else {
const char *cwd = get_pwd_cwd();
if (!cwd)
die("Cannot determine the current working directory");
if (snprintf(buf, PATH_MAX, "%s/%s", cwd, path) >= PATH_MAX)
die("Too long path: %.*s", 60, path);
}
return buf;
}
char *system_path(const char *path)
{
char *buf = NULL;
if (is_absolute_path(path))
return strdup(path);
astrcatf(&buf, "%s/%s", subcmd_config.prefix, path);
return buf;
}
const char *extract_argv0_path(const char *argv0)
{
const char *slash;
if (!argv0 || !*argv0)
return NULL;
slash = argv0 + strlen(argv0);
while (argv0 <= slash && !is_dir_sep(*slash))
slash--;
if (slash >= argv0) {
argv0_path = strndup(argv0, slash - argv0);
return argv0_path ? slash + 1 : NULL;
}
return argv0;
}
void set_argv_exec_path(const char *exec_path)
{
argv_exec_path = exec_path;
/*
* Propagate this setting to external programs.
*/
setenv(subcmd_config.exec_path_env, exec_path, 1);
}
/* Returns the highest-priority location to look for subprograms. */
char *get_argv_exec_path(void)
{
char *env;
if (argv_exec_path)
return strdup(argv_exec_path);
env = getenv(subcmd_config.exec_path_env);
if (env && *env)
return strdup(env);
return system_path(subcmd_config.exec_path);
}
static void add_path(char **out, const char *path)
{
if (path && *path) {
if (is_absolute_path(path))
astrcat(out, path);
else
astrcat(out, make_nonrelative_path(path));
astrcat(out, ":");
}
}
void setup_path(void)
{
const char *old_path = getenv("PATH");
char *new_path = NULL;
char *tmp = get_argv_exec_path();
add_path(&new_path, tmp);
add_path(&new_path, argv0_path);
free(tmp);
if (old_path)
astrcat(&new_path, old_path);
else
astrcat(&new_path, "/usr/local/bin:/usr/bin:/bin");
setenv("PATH", new_path, 1);
free(new_path);
}
static const char **prepare_exec_cmd(const char **argv)
{
int argc;
const char **nargv;
for (argc = 0; argv[argc]; argc++)
; /* just counting */
nargv = malloc(sizeof(*nargv) * (argc + 2));
nargv[0] = subcmd_config.exec_name;
for (argc = 0; argv[argc]; argc++)
nargv[argc + 1] = argv[argc];
nargv[argc + 1] = NULL;
return nargv;
}
int execv_cmd(const char **argv) {
const char **nargv = prepare_exec_cmd(argv);
/* execvp() can only ever return if it fails */
execvp(subcmd_config.exec_name, (char **)nargv);
free(nargv);
return -1;
}
int execl_cmd(const char *cmd,...)
{
int argc;
const char *argv[MAX_ARGS + 1];
const char *arg;
va_list param;
va_start(param, cmd);
argv[0] = cmd;
argc = 1;
while (argc < MAX_ARGS) {
arg = argv[argc++] = va_arg(param, char *);
if (!arg)
break;
}
va_end(param);
if (MAX_ARGS <= argc) {
fprintf(stderr, " Error: too many args to run %s\n", cmd);
return -1;
}
argv[argc] = NULL;
return execv_cmd(argv);
}
|
