56 lines
2.7 KiB
C
56 lines
2.7 KiB
C
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/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
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│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
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╞══════════════════════════════════════════════════════════════════════════════╡
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│ Copyright 2020 Justine Alexandra Roberts Tunney │
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│ │
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│ This program is free software; you can redistribute it and/or modify │
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│ it under the terms of the GNU General Public License as published by │
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│ the Free Software Foundation; version 2 of the License. │
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│ │
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│ This program is distributed in the hope that it will be useful, but │
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│ WITHOUT ANY WARRANTY; without even the implied warranty of │
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│ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU │
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│ General Public License for more details. │
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│ │
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│ You should have received a copy of the GNU General Public License │
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│ along with this program; if not, write to the Free Software │
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│ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA │
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│ 02110-1301 USA │
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╚─────────────────────────────────────────────────────────────────────────────*/
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#include "libc/calls/calls.h"
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#include "libc/errno.h"
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#include "libc/log/check.h"
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#include "libc/runtime/runtime.h"
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#include "libc/str/str.h"
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#include "libc/sysv/consts/o.h"
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/**
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* Removes file system caches from RAM.
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*
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* make o//tool/build/dropcache.com
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* sudo mv o//tool/build/dropcache.com /usr/local/bin/
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* sudo chown root /usr/local/bin/dropcache.com
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* sudo chmod u+s /usr/local/bin/dropcache.com
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*/
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static void Write(int fd, const char *s) {
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write(fd, s, strlen(s));
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}
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int main(int argc, char *argv[]) {
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int fd;
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sync();
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fd = open("/proc/sys/vm/drop_caches", O_WRONLY);
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if (fd == -1) {
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if (errno == EACCES) {
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Write(1, "error: need root privileges\n");
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} else if (errno == ENOENT) {
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Write(1, "error: need /proc filesystem\n");
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}
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exit(1);
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}
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Write(fd, "3\n");
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close(fd);
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return 0;
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}
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