dirname, basename - Parse pathname components
char *dirname(char *path);
char *basename(char *path);
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.
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
Concatenating the string returned by dirname, a "/", and the string
returned by basename yields a complete pathname.
Both dirname and basename may modify the contents of path, so if you
need to preserve the pathname string, copies should be passed to these
functions. Furthermore, dirname and basename may return pointers to
statically allocated memory which may overwritten by subsequent calls.
The following list of examples (taken from SUSv2) shows the strings
returned by dirname and basename for different paths:
path dirname basename
"/usr/lib" "/usr" "lib"
"/usr/" "/" "usr"
"usr" "." "usr"
"/" "/" "/"
"." "." "."
".." "." ".."
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);
Both dirname and basename return pointers to null-terminated strings.
In versions of glibc up to and including 2.2.1, dirname does not correctly
handle pathnames with trailing '/' characters, and generates a
segmentation violation if given a NULL argument.
GNU 2000-12-14 DIRNAME(3)
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