55 lines
2.6 KiB
C
55 lines
2.6 KiB
C
/*-*- 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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│ Permission to use, copy, modify, and/or distribute this software for │
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│ any purpose with or without fee is hereby granted, provided that the │
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│ above copyright notice and this permission notice appear in all copies. │
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│ │
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│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
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│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
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│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
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│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
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│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
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│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
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│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
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│ PERFORMANCE OF THIS SOFTWARE. │
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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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