1/* $OpenBSD: basename.c,v 1.17 2020/10/20 19:30:14 naddy Exp $ */ 2 3/* 4 * Copyright (c) 1997, 2004 Todd C. Miller <millert@openbsd.org> 5 * 6 * Permission to use, copy, modify, and distribute this software for any 7 * purpose with or without fee is hereby granted, provided that the above 8 * copyright notice and this permission notice appear in all copies. 9 * 10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 17 */ 18 19#include <errno.h> 20#include <libgen.h> 21#include <limits.h> 22#include <string.h> 23 24char * 25basename(char *path) 26{ 27 static char bname[PATH_MAX]; 28 size_t len; 29 const char *endp, *startp; 30 31 /* Empty or NULL string gets treated as "." */ 32 if (path == NULL || *path == '\0') { 33 bname[0] = '.'; 34 bname[1] = '\0'; 35 return (bname); 36 } 37 38 /* Strip any trailing slashes */ 39 endp = path + strlen(path) - 1; 40 while (endp > path && *endp == '/') 41 endp--; 42 43 /* All slashes becomes "/" */ 44 if (endp == path && *endp == '/') { 45 bname[0] = '/'; 46 bname[1] = '\0'; 47 return (bname); 48 } 49 50 /* Find the start of the base */ 51 startp = endp; 52 while (startp > path && *(startp - 1) != '/') 53 startp--; 54 55 len = endp - startp + 1; 56 if (len >= sizeof(bname)) { 57 errno = ENAMETOOLONG; 58 return (NULL); 59 } 60 memcpy(bname, startp, len); 61 bname[len] = '\0'; 62 return (bname); 63} 64