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6a032d81 | 1 | /* Copyright (C) 1991, 1992, 1995, 1996 Free Software Foundation, Inc. |
28f540f4 RM |
2 | This file is part of the GNU C Library. |
3 | ||
4 | The GNU C Library is free software; you can redistribute it and/or | |
5 | modify it under the terms of the GNU Library General Public License as | |
6 | published by the Free Software Foundation; either version 2 of the | |
7 | License, or (at your option) any later version. | |
8 | ||
9 | The GNU C Library is distributed in the hope that it will be useful, | |
10 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
12 | Library General Public License for more details. | |
13 | ||
14 | You should have received a copy of the GNU Library General Public | |
15 | License along with the GNU C Library; see the file COPYING.LIB. If | |
16 | not, write to the Free Software Foundation, Inc., 675 Mass Ave, | |
17 | Cambridge, MA 02139, USA. */ | |
18 | ||
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19 | #include <unistd.h> |
20 | #include <stdarg.h> | |
21 | #include <stdlib.h> | |
22 | #include <string.h> | |
60092701 | 23 | #include <errno.h> |
6a032d81 | 24 | #include <paths.h> |
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25 | |
26 | /* Execute FILE, searching in the `PATH' environment variable if it contains | |
27 | no slashes, with arguments ARGV and environment from `environ'. */ | |
28 | int | |
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29 | execvp (file, argv) |
30 | const char *file; | |
31 | char *const argv[]; | |
28f540f4 | 32 | { |
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33 | int got_eacces = 0; |
34 | ||
6a032d81 RM |
35 | void execute (const char *file, char *const argv[]) |
36 | { | |
37 | execv (file, argv); | |
38 | ||
39 | if (errno == ENOEXEC) | |
40 | { | |
41 | /* The file is accessible but it is not an executable file. | |
42 | Invoke the shell to interpret it as a script. */ | |
43 | ||
6a032d81 | 44 | /* Count the arguments. */ |
a1c46301 RM |
45 | int argc = 0; |
46 | while (argv[argc++]) | |
47 | ; | |
6a032d81 RM |
48 | |
49 | /* Construct an argument list for the shell. */ | |
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50 | { |
51 | char *new_argv[argc + 1]; | |
52 | new_argv[0] = (char *) _PATH_BSHELL; | |
53 | new_argv[1] = (char *) file; | |
54 | while (argc > 1) | |
55 | { | |
56 | new_argv[argc] = argv[argc - 1]; | |
57 | --argc; | |
58 | } | |
59 | ||
60 | /* Execute the shell. */ | |
61 | execv (new_argv[0], new_argv); | |
62 | } | |
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63 | } |
64 | } | |
65 | ||
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66 | if (strchr (file, '/') != NULL) |
67 | /* Don't search when it contains a slash. */ | |
6a032d81 | 68 | execute (file, argv); |
c4bf5a3e | 69 | else |
28f540f4 | 70 | { |
c4bf5a3e | 71 | char *path, *p, *name; |
28f540f4 | 72 | size_t len; |
28f540f4 RM |
73 | |
74 | path = getenv ("PATH"); | |
75 | if (path == NULL) | |
76 | { | |
77 | /* There is no `PATH' in the environment. | |
78 | The default search path is the current directory | |
79 | followed by the path `confstr' returns for `_CS_PATH'. */ | |
80 | len = confstr (_CS_PATH, (char *) NULL, 0); | |
81 | path = (char *) __alloca (1 + len); | |
82 | path[0] = ':'; | |
83 | (void) confstr (_CS_PATH, path + 1, len); | |
84 | } | |
85 | ||
86 | len = strlen (file) + 1; | |
87 | name = __alloca (strlen (path) + len); | |
28f540f4 RM |
88 | p = path; |
89 | do | |
90 | { | |
91 | path = p; | |
92 | p = strchr (path, ':'); | |
93 | if (p == NULL) | |
94 | p = strchr (path, '\0'); | |
95 | ||
96 | if (p == path) | |
97 | /* Two adjacent colons, or a colon at the beginning or the end | |
98 | of `PATH' means to search the current directory. */ | |
99 | (void) memcpy (name, file, len); | |
100 | else | |
101 | { | |
102 | /* Construct the pathname to try. */ | |
103 | (void) memcpy (name, path, p - path); | |
104 | name[p - path] = '/'; | |
105 | (void) memcpy (&name[(p - path) + 1], file, len); | |
106 | } | |
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107 | |
108 | /* Try to execute this name. If it works, execv will not return. */ | |
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109 | execute (name, argv); |
110 | ||
111 | switch (errno) | |
112 | { | |
6a032d81 | 113 | case EACCES: |
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114 | /* Record the we got a `Permission denied' error. If we end |
115 | up finding no executable we can use, we want to diagnose | |
116 | that we did find one but were denied access. */ | |
117 | got_eacces = 1; | |
118 | case ENOENT: | |
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119 | /* Those errors indicate the file is missing or not executable |
120 | by us, in which case we want to just try the next path | |
121 | directory. */ | |
122 | break; | |
123 | ||
124 | default: | |
125 | /* Some other error means we found an executable file, but | |
126 | something went wrong executing it; return the error to our | |
127 | caller. */ | |
128 | return -1; | |
129 | } | |
28f540f4 RM |
130 | } |
131 | while (*p++ != '\0'); | |
132 | } | |
133 | ||
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134 | /* We tried every element and none of them worked. */ |
135 | ||
136 | if (got_eacces) | |
137 | /* At least one failure was due to permissions, so report that error. */ | |
c4029823 | 138 | __set_errno (EACCES); |
a1c46301 RM |
139 | |
140 | /* Return the error from the last attempt (probably ENOENT). */ | |
c4bf5a3e | 141 | return -1; |
28f540f4 | 142 | } |