Contents of /trunk/mkinitrd-magellan/klibc/usr/klibc/execvpe.c
Parent Directory | Revision Log
Revision 532 -
(show annotations)
(download)
Sat Sep 1 22:45:15 2007 UTC (16 years, 8 months ago) by niro
File MIME type: text/plain
File size: 1952 byte(s)
Sat Sep 1 22:45:15 2007 UTC (16 years, 8 months ago) by niro
File MIME type: text/plain
File size: 1952 byte(s)
-import if magellan mkinitrd; it is a fork of redhats mkinitrd-5.0.8 with all magellan patches and features; deprecates magellan-src/mkinitrd
1 | /* |
2 | * execvpe.c |
3 | * |
4 | * execvpe() function (from which we build execlp, execlpe, execvp). |
5 | * |
6 | * This version of execvpe() will *not* spawn /bin/sh if the command |
7 | * return ENOEXEC. That's what #! is for, folks! |
8 | * |
9 | * Since execlpe() and execvpe() aren't in POSIX, nor in glibc, |
10 | * I have followed QNX precedent in the implementation of the PATH: |
11 | * the PATH that is used is the one in the current environment, not |
12 | * in the new environment. Otherwise it would be impossible to pass |
13 | * a different PATH to the new process than the one one would want to |
14 | * use to search. |
15 | */ |
16 | |
17 | #include <errno.h> |
18 | #include <unistd.h> |
19 | #include <stdlib.h> |
20 | #include <string.h> |
21 | #include <limits.h> |
22 | |
23 | #define DEFAULT_PATH "/bin:/usr/bin:." |
24 | |
25 | int execvpe(const char *file, char *const *argv, char *const *envp) |
26 | { |
27 | char path[PATH_MAX]; |
28 | const char *searchpath, *esp; |
29 | size_t prefixlen, filelen, totallen; |
30 | |
31 | if (strchr(file, '/')) /* Specific path */ |
32 | return execve(file, argv, envp); |
33 | |
34 | filelen = strlen(file); |
35 | |
36 | searchpath = getenv("PATH"); |
37 | if (!searchpath) |
38 | searchpath = DEFAULT_PATH; |
39 | |
40 | errno = ENOENT; /* Default errno, if execve() doesn't |
41 | change it */ |
42 | |
43 | do { |
44 | esp = strchr(searchpath, ':'); |
45 | if (esp) |
46 | prefixlen = esp - searchpath; |
47 | else |
48 | prefixlen = strlen(searchpath); |
49 | |
50 | if (prefixlen == 0 || searchpath[prefixlen - 1] == '/') { |
51 | totallen = prefixlen + filelen; |
52 | if (totallen >= PATH_MAX) |
53 | continue; |
54 | memcpy(path, searchpath, prefixlen); |
55 | memcpy(path + prefixlen, file, filelen); |
56 | } else { |
57 | totallen = prefixlen + filelen + 1; |
58 | if (totallen >= PATH_MAX) |
59 | continue; |
60 | memcpy(path, searchpath, prefixlen); |
61 | path[prefixlen] = '/'; |
62 | memcpy(path + prefixlen + 1, file, filelen); |
63 | } |
64 | path[totallen] = '\0'; |
65 | |
66 | execve(path, argv, envp); |
67 | if (errno == E2BIG || errno == ENOEXEC || |
68 | errno == ENOMEM || errno == ETXTBSY) |
69 | break; /* Report this as an error, no more search */ |
70 | |
71 | searchpath = esp + 1; |
72 | } while (esp); |
73 | |
74 | return -1; |
75 | } |