Commit | Line | Data |
---|---|---|
42351701 | 1 | /* @(#)exec.c 4.2 (Berkeley) %G% */ |
a69e788c BJ |
2 | /* |
3 | * execlp(name, arg,...,0) (like execl, but does path search) | |
4 | * execvp(name, argv) (like execv, but does path search) | |
5 | */ | |
6 | #include <errno.h> | |
7 | #define NULL 0 | |
8 | ||
9 | static char shell[] = "/bin/sh"; | |
10 | char *execat(), *getenv(); | |
11 | extern errno; | |
12 | ||
13 | execlp(name, argv) | |
14 | char *name, *argv; | |
15 | { | |
16 | return(execvp(name, &argv)); | |
17 | } | |
18 | ||
19 | execvp(name, argv) | |
20 | char *name, **argv; | |
21 | { | |
22 | char *pathstr; | |
23 | register char *cp; | |
24 | char fname[128]; | |
25 | char *newargs[256]; | |
26 | int i; | |
27 | register unsigned etxtbsy = 1; | |
28 | register eacces = 0; | |
29 | ||
30 | if ((pathstr = getenv("PATH")) == NULL) | |
31 | pathstr = ":/bin:/usr/bin"; | |
32 | cp = index(name, '/')? "": pathstr; | |
33 | ||
34 | do { | |
35 | cp = execat(cp, name, fname); | |
36 | retry: | |
37 | execv(fname, argv); | |
38 | switch(errno) { | |
39 | case ENOEXEC: | |
40 | newargs[0] = "sh"; | |
41 | newargs[1] = fname; | |
42 | for (i=1; newargs[i+1]=argv[i]; i++) { | |
43 | if (i>=254) { | |
44 | errno = E2BIG; | |
45 | return(-1); | |
46 | } | |
47 | } | |
48 | execv(shell, newargs); | |
49 | return(-1); | |
50 | case ETXTBSY: | |
51 | if (++etxtbsy > 5) | |
52 | return(-1); | |
53 | sleep(etxtbsy); | |
54 | goto retry; | |
55 | case EACCES: | |
56 | eacces++; | |
57 | break; | |
58 | case ENOMEM: | |
59 | case E2BIG: | |
60 | return(-1); | |
61 | } | |
62 | } while (cp); | |
63 | if (eacces) | |
64 | errno = EACCES; | |
65 | return(-1); | |
66 | } | |
67 | ||
68 | static char * | |
69 | execat(s1, s2, si) | |
70 | register char *s1, *s2; | |
71 | char *si; | |
72 | { | |
73 | register char *s; | |
74 | ||
75 | s = si; | |
42351701 | 76 | while (*s1 && *s1 != ':') |
a69e788c BJ |
77 | *s++ = *s1++; |
78 | if (si != s) | |
79 | *s++ = '/'; | |
80 | while (*s2) | |
81 | *s++ = *s2++; | |
82 | *s = '\0'; | |
83 | return(*s1? ++s1: 0); | |
84 | } |