54 lines
849 B
C
54 lines
849 B
C
#include <stdio.h>
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <fcntl.h>
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#include <unistd.h>
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#include <sys/mman.h>
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int main(int argc, char *argv[]) {
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if (argc < 2) {
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fprintf(stderr, "usage: %s <file>\n", argv[0]);
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return 1;
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}
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int fd = open(argv[1], O_RDONLY);
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if (fd == -1) {
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perror("open");
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return 1;
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}
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struct stat sb;
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if (fstat(fd, &sb) == -1) {
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perror("fstat");
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return 1;
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}
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if (!S_ISREG(sb.st_mode)) {
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fprintf(stderr, "%s is not a file\n", argv[1]);
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return 1;
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}
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char *p = (char *)mmap(0, sb.st_size, PROT_READ, MAP_SHARED, fd, 0);
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if (p == MAP_FAILED) {
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perror("mmap");
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return 1;
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}
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if (close(fd) == -1) {
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perror("close");
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return 1;
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}
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for (int len = 0; len < sb.st_size; len++) {
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putchar(p[len]);
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}
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if (munmap(p, sb.st_size) == -1) {
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perror("munmap");
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return 1;
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}
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return 0;
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}
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