How To Obtain File Name in C?

htabesh · 06-22-2009, 08:55 AM

How Can I Obtain file name (file name and extension) from a path?
for example:

path = /var/www/index.html

Code:

FILE *fp=fopen("/var/www/index.html","w");

I need "index.html"

thanks.

kellinwood · 06-22-2009, 09:05 AM

Code:

#include <strings.h>
#include <string.h>

int last_slash_pos = rindex( path, '/')
char* filename = strdup( &path[ last_slash_pos+1])

Hko · 06-22-2009, 09:25 AM

Quote:

Originally Posted by kellinwood

Code:

int last_slash_pos = rindex[/b]( path, '/')

No. rindex() does not return int, but char*.
Also, strrchr() does the same thing but is better supported along different unix-like OS's.

If you are not changing the string path or filename you can just do:

Code:

#include <string.h>
#include <stdio.h>

int main()
{
    char *path;
    char *filename;

    path = "/var/www/index.html";
    filename = strrchr(path, '/') + 1;
    printf("Filename: %s\n", filename);
    return 0;
}

Only if you do need to change the string path or filename, you can duplicate the string filename with strdup(). In that case, don't forget to free() the dynamically allocated memory.

Code:

#include <string.h>
#include <stdio.h>
#include <stdlib.h>

int main()
{
    char *path;
    char *filename;

    path = "/var/www/index.html";
    filename = strdup(strrchr(path, '/') + 1);
    printf("Filename: %s\n", filename);
    free(filename);
    return 0;
}

AnanthaP · 06-23-2009, 05:46 AM

Dirname, basename
?

dwhitney67 · 06-23-2009, 07:31 AM

Quote:

Originally Posted by AnanthaP

Dirname, basename
?

Yep, that would've been my first instinct too. But it may not be as portable as the other solutions presented.

In case the OP is working under a Linux-only environment, then here's the solution using basename():

Code:

#ifndef _GNU_SOURCE
#define _GNU_SOURCE
#endif
#include <string.h>
#include <stdio.h>

int main()
{
  const char* longpath = "/var/www/index.html";
  const char* filename = basename(longpath);

  printf("filename = %s\n", filename);

  return 0;
}