projects / unix-history / blame
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1 | /*- |
| 2 | * Copyright (c) 1991 The Regents of the University of California. | |
| 3 | * All rights reserved. | |
| 4 | * | |
| 5 | * %sccs.include.redist.c% | |
| 6 | */ | |
| 7 | ||
| 8 | #ifndef lint | |
| c69482b5 | 9 | static char sccsid[] = "@(#)path.c 5.2 (Berkeley) %G%"; |
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10 | #endif /* not lint */ |
| 11 | ||
| 12 | #include <sys/param.h> | |
| 8d4509b6 | 13 | #include <string.h> |
| c69482b5 | 14 | #include "extern.h" |
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15 | |
| 16 | /* | |
| 17 | * These functions manipulate paths in PATH_T structures. | |
| 18 | * | |
| 19 | * They eliminate multiple slashes in paths when they notice them, | |
| 20 | * and keep the path non-slash terminated. | |
| 21 | * | |
| 22 | * Both path_set() and path_append() return 0 if the requested name | |
| 23 | * would be too long. | |
| 24 | */ | |
| 25 | ||
| 26 | #define STRIP_TRAILING_SLASH(p) { \ | |
| 27 | while ((p)->p_end > (p)->p_path && (p)->p_end[-1] == '/') \ | |
| 28 | *--(p)->p_end = 0; \ | |
| 29 | } | |
| 30 | ||
| 31 | /* | |
| 32 | * Move specified string into path. Convert "" to "." to handle BSD | |
| 33 | * semantics for a null path. Strip trailing slashes. | |
| 34 | */ | |
| c69482b5 | 35 | int |
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36 | path_set(p, string) |
| 37 | register PATH_T *p; | |
| 38 | char *string; | |
| 39 | { | |
| 40 | if (strlen(string) > MAXPATHLEN) { | |
| c69482b5 | 41 | err("%s: name too long", string); |
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42 | return(0); |
| 43 | } | |
| 44 | ||
| 45 | (void)strcpy(p->p_path, string); | |
| 46 | p->p_end = p->p_path + strlen(p->p_path); | |
| 47 | ||
| 48 | if (p->p_path == p->p_end) { | |
| 49 | *p->p_end++ = '.'; | |
| 50 | *p->p_end = 0; | |
| 51 | } | |
| 52 | ||
| 53 | STRIP_TRAILING_SLASH(p); | |
| 54 | return(1); | |
| 55 | } | |
| 56 | ||
| 57 | /* | |
| 58 | * Append specified string to path, inserting '/' if necessary. Return a | |
| 59 | * pointer to the old end of path for restoration. | |
| 60 | */ | |
| 61 | char * | |
| 62 | path_append(p, name, len) | |
| 63 | register PATH_T *p; | |
| 64 | char *name; | |
| 65 | int len; | |
| 66 | { | |
| 67 | char *old; | |
| 68 | ||
| 69 | old = p->p_end; | |
| 70 | if (len == -1) | |
| 71 | len = strlen(name); | |
| 72 | ||
| 73 | /* The "+ 1" accounts for the '/' between old path and name. */ | |
| 74 | if ((len + p->p_end - p->p_path + 1) > MAXPATHLEN) { | |
| c69482b5 | 75 | err("%s/%s: name too long", p->p_path, name); |
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76 | return(0); |
| 77 | } | |
| 78 | ||
| 79 | /* | |
| 80 | * This code should always be executed, since paths shouldn't | |
| 81 | * end in '/'. | |
| 82 | */ | |
| 83 | if (p->p_end[-1] != '/') { | |
| 84 | *p->p_end++ = '/'; | |
| 85 | *p->p_end = 0; | |
| 86 | } | |
| 87 | ||
| 88 | (void)strncat(p->p_end, name, len); | |
| 89 | p->p_end += len; | |
| 90 | *p->p_end = 0; | |
| 91 | ||
| 92 | STRIP_TRAILING_SLASH(p); | |
| 93 | return(old); | |
| 94 | } | |
| 95 | ||
| 96 | /* | |
| 97 | * Restore path to previous value. (As returned by path_append.) | |
| 98 | */ | |
| 99 | void | |
| 100 | path_restore(p, old) | |
| 101 | PATH_T *p; | |
| 102 | char *old; | |
| 103 | { | |
| 104 | p->p_end = old; | |
| 105 | *p->p_end = 0; | |
| 106 | } | |
| 107 | ||
| 108 | /* | |
| 109 | * Return basename of path. | |
| 110 | */ | |
| 111 | char * | |
| 112 | path_basename(p) | |
| 113 | PATH_T *p; | |
| 114 | { | |
| 115 | char *basename; | |
| 116 | ||
| 117 | basename = rindex(p->p_path, '/'); | |
| 118 | return(basename ? basename + 1 : p->p_path); | |
| 119 | } |