66 lines
1.3 KiB
C
66 lines
1.3 KiB
C
/*
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* SPDX-License-Identifier: MIT
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* Copyright (c) 2025 Fabio Scotto di Santolo
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*/
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#include <errno.h>
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#include <fcntl.h>
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#include <stddef.h>
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#include <stdio.h>
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#include <string.h>
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#include <unistd.h>
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int main(void)
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{
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printf("Try to open file read.txt\n");
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int fd = open("read.txt", O_RDONLY);
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if (fd == -1) {
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perror("Failed to open read.txt");
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return -1;
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}
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printf("Open file success\n");
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int len;
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if ((len = lseek(fd, 0, SEEK_END)) == -1) {
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perror("Failed to move cursor at end of read.txt file");
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return -1;
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}
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printf("File size of %d bytes\n", len);
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if (lseek(fd, 0, SEEK_SET) == -1) {
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perror("Failed to move cursor at start of read.txt file");
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return -1;
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}
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printf("Reading file read.txt\n");
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char buf[len + 1];
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memset(buf, 0, sizeof(buf));
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size_t bytes_read_total = 0;
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ssize_t ret;
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while (bytes_read_total < len &&
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(ret = read(fd, buf + bytes_read_total,
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len - bytes_read_total)) != 0) {
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if (ret == -1) {
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if (errno == EINTR)
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continue;
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perror("Failed to read read.txt");
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break;
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}
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bytes_read_total += ret;
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}
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buf[bytes_read_total] = '\0';
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printf("File text is:\n\"%s\"\n", buf);
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printf("Close file read.txt\n");
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if (close(fd) == -1) {
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perror("Failed to close read.txt");
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return -1;
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}
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return 0;
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}
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