Thread: warning: unknown escape sequence

Hi everyone,

I'm doing some file input/output work here in C and received this warning during compilation (GCC). My research indicates that this error is in response to white space or a character cancellation function or something like that. I'm not 100% sure exactly what it means. I was hoping some of you could help! My code works fine, but the following warning does appear.

Code:

warning: unknown escape sequence: '\040'

Here's my code (excluding a bunch of comments at the bottom of the file).

Code:

#include <stdio.h>


int main(void){
    FILE *file;
    file = fopen("Running\ Practice.c", "a");
    fprintf(file, "Testing...\n");
    fclose(file);
}

I believe the error I received has to do with either the '\n' I used when appending text to my file, or something to do with there being a space in the file name itself.

Any information (in lamen's terms if possible), would be greatly appreciated!

Thanks,
Harvey

Right so, Salem, would I be able to leave it as 'Running Practice.' or do I need the double backslashes? Also, I apologize about the double post. When I posted this thread, I'd receive an error and it posted twice and I couldn't open either of these two threads. Not sure why that is.

Originally Posted by c99tutorial

On Windows, the \ separates path elements. So if you have a folder called "my dir" and you want to open a file inside that called "my file.txt" you might do the following:

Code:

FILE *fp = fopen("my dir\\my file.txt","a");

However, Windows also accepts '/' as the separator, along with Linux, MacOS, FreeBSD, etc... so it would be better to just use this so that it works on all common systems:

Code:

FILE *fp = fopen("my dir/my file.txt","a");

Oh, okay. I'm actually using Linux and the file name is 'Running Practice.c' in the directory 'Running Practice'. I currently use the backslash in both the file name and the directory, but will try with just the directory in the future.

Cheers!