Removing trailing newline character from fgets() input

sfactor picture sfactor · Apr 22, 2010 · Viewed 358.2k times · Source

I am trying to get some data from the user and send it to another function in gcc. The code is something like this.

printf("Enter your Name: ");
if (!(fgets(Name, sizeof Name, stdin) != NULL)) {
    fprintf(stderr, "Error reading Name.\n");
    exit(1);
}

However, I find that it has a newline \n character in the end. So if I enter John it ends up sending John\n. How do I remove that \n and send a proper string.

Answer

Tim Čas picture Tim Čas · Feb 11, 2015

Perhaps the simplest solution uses one of my favorite little-known functions, strcspn():

buffer[strcspn(buffer, "\n")] = 0;

If you want it to also handle '\r' (say, if the stream is binary):

buffer[strcspn(buffer, "\r\n")] = 0; // works for LF, CR, CRLF, LFCR, ...

The function counts the number of characters until it hits a '\r' or a '\n' (in other words, it finds the first '\r' or '\n'). If it doesn't hit anything, it stops at the '\0' (returning the length of the string).

Note that this works fine even if there is no newline, because strcspn stops at a '\0'. In that case, the entire line is simply replacing '\0' with '\0'.