mirror of https://github.com/golang/go.git
88 lines
2.2 KiB
C
88 lines
2.2 KiB
C
/*
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Plan 9 from User Space src/lib9/open.c
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http://code.swtch.com/plan9port/src/tip/src/lib9/open.c
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Copyright 2001-2007 Russ Cox. All Rights Reserved.
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Permission is hereby granted, free of charge, to any person obtaining a copy
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of this software and associated documentation files (the "Software"), to deal
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in the Software without restriction, including without limitation the rights
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to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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copies of the Software, and to permit persons to whom the Software is
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furnished to do so, subject to the following conditions:
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The above copyright notice and this permission notice shall be included in
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all copies or substantial portions of the Software.
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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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THE SOFTWARE.
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*/
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#define _GNU_SOURCE /* for Linux O_DIRECT */
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#include <u.h>
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#define NOPLAN9DEFINES
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#include <sys/file.h>
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#include <libc.h>
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#ifndef O_DIRECT
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#define O_DIRECT 0
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#endif
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int
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p9open(char *name, int mode)
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{
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int cexec, rclose;
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int fd, umode, lock, rdwr;
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struct flock fl;
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rdwr = mode&3;
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umode = rdwr;
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cexec = mode&OCEXEC;
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rclose = mode&ORCLOSE;
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lock = mode&OLOCK;
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mode &= ~(3|OCEXEC|ORCLOSE|OLOCK);
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if(mode&OTRUNC){
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umode |= O_TRUNC;
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mode ^= OTRUNC;
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}
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if(mode&ODIRECT){
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umode |= O_DIRECT;
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mode ^= ODIRECT;
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}
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if(mode&ONONBLOCK){
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umode |= O_NONBLOCK;
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mode ^= ONONBLOCK;
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}
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if(mode&OAPPEND){
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umode |= O_APPEND;
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mode ^= OAPPEND;
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}
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if(mode){
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werrstr("mode 0x%x not supported", mode);
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return -1;
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}
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fd = open(name, umode);
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if(fd >= 0){
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if(lock){
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fl.l_type = (rdwr==OREAD) ? F_RDLCK : F_WRLCK;
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fl.l_whence = SEEK_SET;
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fl.l_start = 0;
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fl.l_len = 0;
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if(fcntl(fd, F_SETLK, &fl) < 0){
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close(fd);
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werrstr("lock: %r");
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return -1;
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}
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}
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if(cexec)
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fcntl(fd, F_SETFL, FD_CLOEXEC);
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if(rclose)
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remove(name);
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}
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return fd;
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}
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