NAME top
basename, dirname - parse pathname components
SYNOPSIS top
#include <libgen.h>
char *dirname(char *path);
char *basename(char *path);
DESCRIPTION top
Warning: there are two different functions basename() - see below.
注意：这里有两个不同的函数都叫做basename()-请看下面
The functions dirname() and basename() break a null-terminated
pathname string into directory and filename components. In the usual
case, dirname() returns the string up to, but not including, the
final '/', and basename() returns the component following the final
'/'. Trailing '/' characters are not counted as part of the
pathname.
函数dirname()和basename()把一个NULL结尾的路径字符串分割成目录和文件名两部分。
通常，dirname()函数返回从开始到最后一个'/'字符，但不包括它的字符串，
basename()函数返回跟在最后一个'/'字符之后的字符串，最后的'/'不当做是文件名的一部分。
If path does not contain a slash, dirname() returns the string "."
while basename() returns a copy of path. If path is the string "/",
then both dirname() and basename() return the string "/". If path is
a null pointer or points to an empty string, then both dirname() and
basename() return the string ".".
如果路径中一个斜线都没有，dirname()函数会返回字符串"."，而basename()会直接返回这个路径。
如果路径是字符串"/"，那么dirname()和basename()都返回字符串"/"。如果路径是一个NULL指针或者指向一个
空字符串，那么dirname()和basename()都返回字符串"."。
Concatenating the string returned by dirname(), a "/", and the string
returned by basename() yields a complete pathname.
连接dirname()返回的字符串，一个"/"，以及basename()返回的字符串，可以组合成一个完整的路径
Both dirname() and basename() may modify the contents of path, so it
may be desirable to pass a copy when calling one of these functions.
diranme()和basename()都有可能修改路径的内容，所以当调用这两个函数时，会返回路径的一个拷贝
These functions may return pointers to statically allocated memory
which may be overwritten by subsequent calls. Alternatively, they
may return a pointer to some part of path, so that the string
referred to by path should not be modified or freed until the pointer
returned by the function is no longer required.
这些函数可能会返回一个指向静态内存的指针，这个静态内存可能会被接下来的条用覆盖掉。
或者它们会返回一个指向路径某些部分的指针，因此这个引用了路径的字符创不能被修改或者释放，直到这个指针
指向的字符创不再被使用
The following list of examples (taken from SUSv2) shows the strings
returned by dirname() and basename() for different paths:
下面的例子给出对于不同的路径，dirname()和basename()的相应返回值
path dirname basename
/usr/lib /usr lib
/usr/ / usr
usr . usr
/ / /
. . .
.. . ..
RETURN VALUE top
Both dirname() and basename() return pointers to null-terminated
strings. (Do not pass these pointers to free(3).)
dirname()和basename()都返回一个指向不以NULL结尾的字符串（不要以这些指针为参数来调用free()）
ATTRIBUTES top
For an explanation of the terms used in this section, see
attributes(7).
┌──────────────────────┬───────────────┬─────────┐
│Interface │ Attribute │ Value │
├──────────────────────┼───────────────┼─────────┤
│basename(), dirname() │ Thread safety │ MT-Safe │
└──────────────────────┴───────────────┴─────────┘
CONFORMING TO top
POSIX.1-2001.
NOTES top
There are two different versions of basename() - the POSIX version
described above, and the GNU version, which one gets after
这里有两个不同版本的basename()，POSIX版本的已经在上面介绍了，GNU版本的将在下面进行介绍
#define _GNU_SOURCE /* See feature_test_macros(7) */
#include <string.h>
The GNU version never modifies its argument, and returns the empty
string when path has a trailing slash, and in particular also when it
is "/". There is no GNU version of dirname().
GNU版本的basename()永远不会修改它的参数，当路径以'/'结尾是，它返回一个空的字符串，而且，当路径只有
一个'/'时，也是返回一个空字符串。没有GNU版本的dirname()
With glibc, one gets the POSIX version of basename() when <libgen.h>
is included, and the GNU version otherwise.
当使用glibc时，当引入了<libgen.h>头文件时，使用POSIX版本，否则使用GNU版本。
BUGS top
In the glibc implementation of the POSIX versions of these functions
they modify their argument, and segfault when called with a static
string like "/usr/". Before glibc 2.2.1, the glibc version of
dirname() did not correctly handle pathnames with trailing '/'
characters, and generated a segfault if given a NULL argument.
EXAMPLE top
char *dirc, *basec, *bname, *dname;
char *path = "/etc/passwd";
dirc = strdup(path);
basec = strdup(path);
dname = dirname(dirc);
bname = basename(basec);
printf("dirname=%s, basename=%s\n", dname, bname);
SEE ALSO top
basename(1), dirname(1)
COLOPHON top
This page is part of release 3.82 of the Linux man-pages project. A
description of the project, information about reporting bugs, and the
latest version of this page, can be found at
http://www.kernel.org/doc/man-pages/.
GNU 2015-03-02 BASENAME(3)
