X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2Fbasename.c;h=426ed40f1a9e19f37abb6be20f72d587a2fc9b8a;hb=1056e42fdb8bb68c6afcdcb3a793558cae08ba44;hp=0fd981f3032e09dbd35c276e6ef6224dcb5d40ce;hpb=c34b054fecc1f90dad141e3e988f357e22f1e473;p=gnulib.git diff --git a/lib/basename.c b/lib/basename.c index 0fd981f30..426ed40f1 100644 --- a/lib/basename.c +++ b/lib/basename.c @@ -1,98 +1,128 @@ -/* basename.c -- return the last element in a path */ +/* basename.c -- return the last element in a file name -#if HAVE_CONFIG_H -# include -#endif + Copyright (C) 1990, 1998, 1999, 2000, 2001, 2003, 2004, 2005, 2006 Free + Software Foundation, Inc. -#ifndef FILESYSTEM_PREFIX_LEN -# define FILESYSTEM_PREFIX_LEN(f) 0 -#endif + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. -#ifndef ISSLASH -# define ISSLASH(c) ((c) == '/') -#endif + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. -/* In general, we can't use the builtin `basename' function if available, - since it has different meanings in different environments. - In some environments the builtin `basename' modifies its argument. */ + You should have received a copy of the GNU General Public License + along with this program. If not, see . */ + +#include + +#include "dirname.h" + +#include +#include "xalloc.h" +#include "xstrndup.h" + +/* Return the address of the last file name component of NAME. If + NAME has no relative file name components because it is a file + system root, return the empty string. */ char * -base_name (name) - char const *name; +last_component (char const *name) { - char const *base = name += FILESYSTEM_PREFIX_LEN (name); + char const *base = name + FILE_SYSTEM_PREFIX_LEN (name); + char const *p; + bool saw_slash = false; - for (; *name; name++) - if (ISSLASH (*name)) - base = name + 1; + while (ISSLASH (*base)) + base++; + + for (p = base; *p; p++) + { + if (ISSLASH (*p)) + saw_slash = true; + else if (saw_slash) + { + base = p; + saw_slash = false; + } + } return (char *) base; } -#ifdef STDC_HEADERS -# include -#else -char *malloc (); -#endif + +/* In general, we can't use the builtin `basename' function if available, + since it has different meanings in different environments. + In some environments the builtin `basename' modifies its argument. + + Return the last file name component of NAME, allocated with + xmalloc. On systems with drive letters, a leading "./" + distinguishes relative names that would otherwise look like a drive + letter. Unlike POSIX basename(), NAME cannot be NULL, + base_name("") returns "", and the first trailing slash is not + stripped. + + If lstat (NAME) would succeed, then { chdir (dir_name (NAME)); + lstat (base_name (NAME)); } will access the same file. Likewise, + if the sequence { chdir (dir_name (NAME)); + rename (base_name (NAME), "foo"); } succeeds, you have renamed NAME + to "foo" in the same directory NAME was in. */ char * -base_name_strip_trailing_slashes (name) - char const *name; +base_name (char const *name) { - char const *end_p = name += FILESYSTEM_PREFIX_LEN (name); - char const *first, *p; - char *base; - int length; - - /* Make END_P point to the byte after the last non-slash character - in NAME if one exists. */ - for (p = name; *p; p++) - if (!ISSLASH (*p)) - end_p = p + 1; - - if (end_p == name) - { - first = end_p; - } - else + char const *base = last_component (name); + size_t length; + + /* If there is no last component, then name is a file system root or the + empty string. */ + if (! *base) + return xstrndup (name, base_len (name)); + + /* Collapse a sequence of trailing slashes into one. */ + length = base_len (base); + if (ISSLASH (base[length])) + length++; + + /* On systems with drive letters, `a/b:c' must return `./b:c' rather + than `b:c' to avoid confusion with a drive letter. On systems + with pure POSIX semantics, this is not an issue. */ + if (FILE_SYSTEM_PREFIX_LEN (base)) { - first = end_p - 1; - while (first > name && !ISSLASH (*(first - 1))) - --first; + char *p = xmalloc (length + 3); + p[0] = '.'; + p[1] = '/'; + memcpy (p + 2, base, length); + p[length + 2] = '\0'; + return p; } - length = end_p - first; - base = (char *) malloc (length + 1); - if (base == 0) - return 0; + /* Finally, copy the basename. */ + return xstrndup (base, length); +} - memcpy (base, first, length); - base[length] = '\0'; +/* Return the length of the basename NAME. Typically NAME is the + value returned by base_name or last_component. Act like strlen + (NAME), except omit all trailing slashes. */ - return base; -} +size_t +base_len (char const *name) +{ + size_t len; + size_t prefix_len = FILE_SYSTEM_PREFIX_LEN (name); -#ifdef TEST -# include -# include + for (len = strlen (name); 1 < len && ISSLASH (name[len - 1]); len--) + continue; -# define CHECK(a,b) assert (strcmp (base_name_strip_trailing_slashes(a), b) \ - == 0) + if (DOUBLE_SLASH_IS_DISTINCT_ROOT && len == 1 + && ISSLASH (name[0]) && ISSLASH (name[1]) && ! name[2]) + return 2; -int -main () -{ - CHECK ("a", "a"); - CHECK ("ab", "ab"); - CHECK ("ab/c", "c"); - CHECK ("/ab/c", "c"); - CHECK ("/ab/c/", "c"); - CHECK ("/ab/c////", "c"); - CHECK ("/", ""); - CHECK ("////", ""); - CHECK ("////a", "a"); - CHECK ("//a//", "a"); - CHECK ("/a", "a"); - exit (0); + if (FILE_SYSTEM_DRIVE_PREFIX_CAN_BE_RELATIVE && prefix_len + && len == prefix_len && ISSLASH (name[prefix_len])) + return prefix_len + 1; + + return len; } -#endif