rename

Defined in header `<stdio.h>`
int rename( const char* old_filename, const char* new_filename );

Changes the filename of a file. The file is identified by character string pointed to by old_filename. The new filename is identified by character string pointed to by new_filename.

If new_filename exists, the behavior is implementation-defined.

Parameters

old_filename	-	pointer to a null-terminated string containing the path identifying the file to rename
new_filename	-	pointer to a null-terminated string containing the new path of the file

Return value

0 upon success or non-zero value on error.

Notes

POSIX specifies many additional details on the semantics of this function.

Example

Run this code

#include <stdio.h>
#include <stdlib.h>
 
int main(void)
{
    FILE* fp = fopen("from.txt", "w"); // create file "from.txt"
    if (!fp)
    {
        perror("from.txt");
        return EXIT_FAILURE;
    }
    fputc('a', fp); // write to "from.txt"
    fclose(fp);
 
    int rc = rename("from.txt", "to.txt");
    if (rc)
    {
        perror("rename");
        return EXIT_FAILURE;
    }
 
    fp = fopen("to.txt", "r");
    if(!fp)
    {
        perror("to.txt");
        return EXIT_FAILURE;
    }
    printf("%c\n", fgetc(fp)); // read from "to.txt"
    fclose(fp);
 
    return EXIT_SUCCESS;
}

Possible output:

References

C23 standard (ISO/IEC 9899:2024):

7.21.4.2 The rename function (p: TBD)

C17 standard (ISO/IEC 9899:2018):

7.21.4.2 The rename function (p: TBD)

C11 standard (ISO/IEC 9899:2011):

7.21.4.2 The rename function (p: 302-303)

C99 standard (ISO/IEC 9899:1999):

7.19.4.2 The rename function (p: 268-269)

C89/C90 standard (ISO/IEC 9899:1990):

4.9.4.2 The rename function

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