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/*
* Copyright 2022 The Emscripten Authors. All rights reserved.
* Emscripten is available under two separate licenses, the MIT license and the
* University of Illinois/NCSA Open Source License. Both these licenses can be
* found in the LICENSE file.
*/
#include <assert.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
const char* file = "/foo.txt";
off_t getPos(int fd) {
errno = 0;
off_t pos = lseek(fd, 0, SEEK_CUR);
assert(pos != (off_t)-1);
assert(errno == 0);
return pos;
}
void setPos(int fd, off_t pos) {
errno = 0;
pos = lseek(fd, pos, SEEK_SET);
assert(pos != (off_t)-1);
assert(errno == 0);
}
int main() {
int fd = open(file, O_RDWR | O_CREAT | O_EXCL | O_APPEND, 0777);
assert(fd > 0);
off_t pos = getPos(fd);
assert(pos == 0);
ssize_t nwritten = write(fd, "hello", 5);
assert(nwritten == 5);
pos = getPos(fd);
assert(pos == 5);
setPos(fd, 0);
pos = getPos(fd);
assert(pos == 0);
nwritten = write(fd, "", 0);
assert(nwritten == 0);
pos = getPos(fd);
assert(pos == 5);
setPos(fd, 0);
pos = getPos(fd);
assert(pos == 0);
nwritten = write(fd, ", world!", 8);
assert(nwritten == 8);
pos = getPos(fd);
assert(pos == 13);
setPos(fd, 42);
pos = getPos(fd);
assert(pos == 42);
nwritten = write(fd, "!!", 2);
assert(nwritten == 2);
pos = getPos(fd);
assert(pos == 15);
setPos(fd, 0);
char buf[100] = {};
ssize_t nread = read(fd, buf, 100);
assert(nread == 15);
assert(strcmp(buf, "hello, world!!!") == 0);
printf("ok\n");
}
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