#include <libgen.h>

char *dirname(char *path);

char *basename(char *path);
 

path        dirname    basename

"/usr/lib"  "/usr"     "lib"

"/usr/"     "/"        "usr"

"usr"       "."        "usr"

"/"         "/"        "/"

"."         "."        "."

".."        "."        ".."

#include <stdio.h>

#include <stdlib.h>

#include <libgen.h>

#include <string.h>

int main ( int argc, char *argv[] )

{

char *str = "/root/workdir/haha.txt";

char buf[] = {};

strncpy (buf, str, strlen(str));

//dirname 会修改buf中的值，所以需要一个缓冲区

//直接调用dirname(str), 会使程序崩溃

printf ("dirstr is:%s\n", dirname(buf));

printf ("dir buf is:%s\n", buf);

//basename 不会修改buf中的值,以下两次调用都是可以的

strncpy (buf, str, strlen(str));

//1次

printf ("test1 basename is:%s\n", basename(buf));

printf ("name buf is:%s\n", buf);

//2次

printf ("test2 basename is:%s\n", basename(str));

return ;

}
 

#include <stdio.h>

#include <string.h>

int main ( int argc, char *argv[] )

{

  char *str = "/hah/test/test.hah.dd.json";

  char *suffix = strrchr (str, '.');

  printf ("suffix is:%s\n", suffix);

  return ;

}