micro-utils/src/nice.c

#include <stdio.h>
#include <errno.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/resource.h>

int main(int argc, char **argv) {
	int oldp = getpriority(PRIO_PROCESS, 0);
	int adj = 10;

	int opt;
	while ((opt = getopt(argc, argv, "n:")) != -1) {
		switch (opt) {
			case 'n':
				adj = atoi(optarg);
				break;

			default:
				puts("nice [n] [cmd] [arg1] [arg2]\n\t-n N Add N to the niceness");
				return 0;
		}
	}

	argv += optind;
	argc -= optind;

	if (argc == 0) {
		printf("%d\n", oldp);
		return 0;
	}

	if (setpriority(PRIO_PROCESS, 0, oldp + adj) < 0) {
		fprintf(stderr, "nice: %s\n", strerror(errno));
		return 1;
	}


	execvp(argv[0], argv);
	fprintf(stderr, "nice: %s: %s\n", argv[0], strerror(errno));

	return 1;
}