sub.c File Reference

#include <stdio.h>
#include <stdlib.h>

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Functions
	main (int argc, char **argv)

Function Documentation

main	(	int	argc,
		char **	argv
	)

Definition at line 29 of file sub.c.

{
    FILE *fp;
    char *buf;
    int size;

    if ((argc < 3) || (argc > 4)) {
        fprintf(stderr, "usage: %s <string> <substitute string> [filename]\n", *argv);
        exit(-1);
    }

    if (argc > 3)
        fp = fopen(argv[3], "r");
    else    fp = stdin;

    size = strlen(argv[1]);
    buf = (char *)calloc(size + 1, 1);

    while ((buf[size - 1] = fgetc(fp)) != EOF) {
        if (!strcmp(buf, argv[1])) {
            printf("\n%s", argv[2]);
            memset(buf, 0, size);
            continue;
        }
        if (*buf) {
            printf("%c", *buf);
        }
        memmove(buf, &buf[1], size);
    }
    buf[size - 1] = 0;
    printf("%s", buf);
}