Program in C

[Henry Chua]

Hi Guys,

Is there anyway I can write a program in C to check whether a file exist in a path?
regards
Henry

[Biswajit Tripathy]

# man 2 stat

- Biswajit

[Amit Agarwal_1 · Accepted solution]

Yes, as Biswajit said "stat()" is the answer. Here is a small program for the same.
================
#include
#include

int main() {

struct stat bstat;

if (stat("filename", &bstat) < 0) {
fprintf(stderr, "file does not exist\n");
} else {
fprintf(stderr, "file does exist\n");
}
}
===========

-Amit

[Muthukumar_5]

If you want to check file availablity with c coding then, you can simply use fopen() also as,

#include

main()
{

FILE *fp;
fp=fopen("filename1","r");
if (!fp){
printf ("Filename filename1 is not existing\n");
} else {
printf ("Filename filename1 is existing\n");
}
}

Change filename1 with full path as like "/tmp/test/filenam1" also in fopen().

hth.

[dirk dierickx]

if you want to write this to incorporate it into a script, you should not waste your time doing so. unix has the 'test' command (man test) which has lots of options for checking files.

[Antoniov.]

Hi Henry,
I used same routine of Muthukumar with fopen function. It works with any c and any platform.

Antonio Vigliotti.

[A. Clay Stephenson]

The stat() system call is a much better choice than fopen. First, it's cheaper in terms of system resources but more importantly, fopen() (or open()) could very easily fail even if the file actually exists. How? You specify a mode (e.g. "r") when using fopen(), if the file exists but has only write or execute bits set, your fopen() will fail. Use stat(); if it returns a zero result then the operation was okay; you then use the mode field to determine if the file is a regular file and has the desired permission bits sets. If stat returns a non-zero result then you look at errno and determine why it failed.

[D Block 2]

I agree w/ Clay.. use the stat(2) system call.. you can also use the fopen(3), if you like.

[Antoniov.]

Clay,
thank you for stat information. I read the help on stat function. I think I'll use that next time.

Antonio Vigliotti

[Stephen Keane]

Don't forget the access(2) system call