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/* See LICENSE file for copyright and license details. */
#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
int
main(int argc, char *argv[])
{
unsigned long i, count;
const char *command, *argv0;
char path[sizeof("/sys/devices/system/cpu/cpu/online") + 3 * sizeof(i)];
int fd, ret = 0;
if (argc == 0) {
wrong_command:
fprintf(stderr, "usage: coreup [count]\nusage: coredown [count]\n");
return 1;
}
argv0 = *argv++;
argc--;
command = strrchr(argv0, '/');
command = command ? &command[1] : argv0;
if (!strcmp(command, "coreup"))
count = ULONG_MAX;
else if (!strcmp(command, "coredown"))
count = 1;
else
goto wrong_command;
if (argc && !strcmp(argv[0], "--")) {
argv++;
argc--;
}
if (argc > 1) {
usage:
fprintf(stderr, "usage: %s [count]\n", argv0);
return 1;
}
if (argc >= 1) {
char *end;
errno = 0;
if (!isdigit(**argv))
goto usage;
count = strtoul(*argv, &end, 10);
if (!count || errno || *end)
goto usage;
argv++;
argc--;
}
for (i = 1; i; i++) {
sprintf(path, "/sys/devices/system/cpu/cpu%zu/online", i);
fd = open(path, O_WRONLY);
if (fd < 0) {
if (errno == ENOENT)
break;
fprintf(stderr, "%s: open %s O_WRONLY\n", argv0, path);
return 1;
}
if (write(fd, i < count ? "1\n" : "0\n", 2) < 0) {
fprintf(stderr, "%s: write %s\n", argv0, path);
ret = 1;
}
close(fd);
}
return ret;
}
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