#define _POSIX_C_SOURCE 201800 /* as before */
#include <pwd.h>   /* getpwnam */
#include <stdio.h> /* printf */

/* This program prints the basic information about a user whose
 * login name is given to it as a command-line argument. */

int main( int argc, const char **argv )
{
    if ( argc != 2 ) /* check command line arguments */
    {
        fputs( "expected 1 username as an argument\n", stderr );
        return 1;
    }

    /* Like ‹getpwuid›, the ‹getpwnam› function looks up user
     * records, but this time by their login (user name). */

    struct passwd *pw = getpwnam( argv[1] );
    printf( "name: %s\n", pw->pw_name );
    printf( "uid: %d\n", pw->pw_uid );
    printf( "gid: %d\n", pw->pw_gid );
    printf( "home: %s\n", pw->pw_dir );
    printf( "shell: %s\n", pw->pw_shell );
    printf( "\n" );
    return 0;
}

/* Next: ‹getgrent.c›. */