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 9 static char sccsid[] = "@(#)path.c 5.2 (Berkeley) 10/27/91"; 10 #endif /* not lint */ 11 12 #include <sys/param.h> 13 #include <string.h> 14 #include "extern.h" 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 */ 35 int 36 path_set(p, string) 37 register PATH_T *p; 38 char *string; 39 { 40 if (strlen(string) > MAXPATHLEN) { 41 err("%s: name too long", string); 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) { 75 err("%s/%s: name too long", p->p_path, name); 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 } 120