files.c

/**
 * @example files.c
 * This example demonstrates when and how the ewarn() function is used.
 *
 * err() is called when a fatal error occurs. ewarn() is called when a nonfatal
 * error occurs.
 *
 * Compare this example with hello.c, which demonstrates warn(). In hello.c,
 * warn() is called after an unusual but managable situation with the program
 * arguments is found. In this example, ewarn() is called after a necessary
 * library function fails. We will get a more detailed error message with
 * ewarn() because it looks at errno when writing its message.
 */
 
#include <stdio.h>
#include <stdlib.h>
 
#include "../err.h"
 
int
main(int argc, char *argv[])
{
        int i;
 
        program_invocation_name = argv[0];
 
        if (argc < 2)
                err("no files provided");
 
        for (i = 1; i < argc; i++) {
                FILE *fp;
                int c;
 
                if ((fp = fopen(argv[i], "r")) == NULL) {
                        ewarn("%s", argv[i]);
                        continue;
                }
 
                while ((c = fgetc(fp)) != EOF)
                        putchar(c);
 
                fclose(fp);
        }
 
        return EXIT_SUCCESS;
}