toaruos/apps/fgrep.c

47 lines
985 B
C

/**
* @brief fgrep - dump grep
*
* Locates strings in files and prints the lines containing them,
* with extra color identification if stdout is a tty.
*
* @copyright
* This file is part of ToaruOS and is released under the terms
* of the NCSA / University of Illinois License - see LICENSE.md
* Copyright (C) 2014-2018 K. Lange
*/
#include <stdio.h>
#include <fcntl.h>
#include <unistd.h>
#include <string.h>
#define LINE_SIZE 4096
int main(int argc, char ** argv) {
if (argc < 2) {
fprintf(stderr, "usage: %s thing-to-grep-for\n", argv[0]);
return 1;
}
char * needle = argv[1];
char buf[LINE_SIZE];
int ret = 1;
int is_tty = isatty(STDOUT_FILENO);
while (fgets(buf, LINE_SIZE, stdin)) {
char * found = strstr(buf, needle);
if (found) {
if (is_tty) {
*found = '\0';
found += strlen(needle);
fprintf(stdout, "%s\033[1;31m%s\033[0m%s", buf, needle, found);
} else {
fprintf(stdout, "%s", buf);
}
ret = 0;
}
}
return ret;
}