Count bytes of filename

Question

How can I know how many bytes does it weight the name of a filename? Just the file, not the full path. I've tried this:

echo 'filename.extension' | wc -c

is this right?

Answer 1

Looks fine; echo will however add a trailing newline by default, so echo -n or printf are your friend. If you want to convert /path/to/files/like/this/filename.extension to filename.extension, you'd have something like

filepath='/path/to/files/like/this/filename.extension'
namelength=$(printf "%s" "$(basename "${filepath}")" | wc -c)

If you want character (or something similar) length, Not byte count:
There's a much easier way in POSIX-compatible shells (like bash and zsh, so you're probably using one!):

filename="${filepath##*/}"
namelength=${#filename}

The ${#varname} expansion directly gives you the length of the variable.

Answer 2

You're not testing a file name, just a string, but what about this, a quick and dirty hack...

#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <string.h>

int main(int argc, char **argv) {
            int fcount = 1;
            int ret = 0;
            struct stat fstat_details;
    
            while (fcount != argc) {
                    ret = stat (argv[fcount], &fstat_details);
    
                    if (ret == 0) {
                            printf ("file: %s, length: %lu\n", argv[fcount], strlen(argv[fcount]));
                    } else {
                            printf ("file %s not found\n", argv[fcount]);
                    }
                    fcount++;
            }
            return(0);
    }