Giacomo Tesio
b862596737
In Plan9 the create syscall fallback on a open(OTRUNC) if the path provided already exists. This is actually a common requirement as most programs (editors, cat...) simply requires that a file is there and is empty, and doesn't care overwriting existing contents (note that this is particularily sensible with something like fossil). In Jehanne the application is responsible of actually handle this "file exists" error but libc provides ocreate() to mimic the Plan9 behaviour. Note that ocreate introduce a subtle race too: the path is walked several times if the file exists, thus it could misbehave on concurrent namespace changes. However I guess this is not going to happen often enough to care now. NOTE we will probably address this rare race too, with a more drammatic change to syscalls: a new walk() syscall that will provide an unopen fd.
57 lines
1.4 KiB
C
57 lines
1.4 KiB
C
/*
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* This file is part of Jehanne.
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*
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* Copyright (C) 2015 Giacomo Tesio <giacomo@tesio.it>
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*
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* Jehanne 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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* Jehanne is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU 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 Jehanne. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include <u.h>
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#include <libc.h>
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/* Test rune assignment: should not produce any warning
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* see https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67132
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*/
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void
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main(void)
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{
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int fd;
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static Rune r[16] = L"Ciao Mondo!";
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static Rune buf[16];
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if((fd = ocreate("/tmp/runetest.txt", OWRITE, 0666L)) < 0) {
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print("FAIL: open: %r\n");
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exits("FAIL");
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}
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if(write(fd, r, sizeof(r)) < 0){
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print("FAIL: fprint: %r\n");
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exits("FAIL");
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}
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close(fd);
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if((fd = open("/tmp/runetest.txt", OREAD)) < 0) {
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print("FAIL: open: %r\n");
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exits("FAIL");
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}
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if(read(fd, (char*)buf, sizeof(buf)) < 0){
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print("FAIL: read: %r\n");
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exits("FAIL");
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}
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close(fd);
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if (runestrcmp(r, buf) != 0){
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print("FAIL: got '%S' instead of '%S'.\n", buf, r);
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exits("FAIL");
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}
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print("PASS\n");
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exits("PASS");
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}
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