cat.c

// source code from K&R 2nd page 162
#include <stdio.h>

/* cat */
int main(int argc, char *argv[])
{
    FILE *fp;
    void filecopy(FILE *, FILE *);

    if (argc == 1)
        filecopy(stdio, stdout);
    else
        while (--argc > 0)
            if ((fp = fopen(*++argv, "r")) == NULL) {
                printf("cat: can't open %s\n", *argv);
                return 1;
            } else {
                filecopy(fp, stdout);
                fclose(fp);
            }
    return 0;
}

/* filecopy */
void filecopy(FILE *ifp, FILE *ofp)
{
    int c;

    while ((c = getc(ifp)) != EOF)
        putc(c, ofp);
}