C Rename File

Summary: in this tutorial, you’ll learn how to use the C rename() function to rename a file.

Introduction to the C rename() function

The rename() function is defined in the stdio.h standard library. The rename() function allows you to change the name of a file to a new one.

The following shows the syntax of the rename() function:

int rename ( const char * oldname, const char * newname );
Code language: C++ (cpp)

The rename() function takes two parameters:

• oldname is the name of the file that you want to rename.
• newname is the new name of the file.

The rename() function returns 0 on success or -1 on failure.

Note that to delete a file, you use the remove() function.

C rename() function example

The following program shows how to use the rename() function to rename the test.txt file in the current directory to new_test.txt file:

#include <stdio.h>

int main()
{
    char *oldname = "test.txt";
    char *newname = "new_test.txt";

    if (rename(oldname, newname) == 0)
        printf("The file %s was renamed to %s.", oldname, newname);
    else
        printf("Error renaming the file %s.", oldname);

    return 0;
}
Code language: C++ (cpp)

If the tets.txt file exists, the program will show the following message:

The file test.txt was renamed to new_test.txt.
Code language: C++ (cpp)

In case an error occurs, for example, the file doesn’t exist or it is locked by another program, you’ll see the following message:

Error renaming the file test.txt
Code language: C++ (cpp)

Summary

• Use the C rename() function from the standard library to rename a file.