56 lines
939 B
C
56 lines
939 B
C
#include <fcntl.h>
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#include <stdio.h>
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#include <errno.h>
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#include <string.h>
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#include <unistd.h>
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unsigned int flag;
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unsigned int lines;
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void cat(const int fd) {
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char buf[4024];
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ssize_t len;
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while ((len = read(fd, buf, sizeof(buf))) > 0) {
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for (ssize_t i = 0; i < len; i++) {
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if (((i > 0) ? buf[i - 1] == '\n' : 1) && flag)
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printf(" %d ", ++lines);
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printf("%c", buf[i]);
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}
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}
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}
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int main(const int argc, const char **argv) {
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int i;
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for (i = 1; i < argc; i++) {
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if (argv[i][0] != '-')
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break;
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else if (!strcmp(argv[i], "-n"))
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flag = 1;
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else if (!strcmp(argv[i], "--help")) {
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printf("cat [-n (numerate)] [file1 file2 ...]\n");
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return 0;
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}
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}
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if (i == argc)
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cat(STDIN_FILENO);
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else {
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for (; i < argc; i++) {
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int fd = open(argv[i], O_RDONLY);
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if (fd < 0) {
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fprintf(stderr, "cat: %s %s\n", argv[i], strerror(errno));
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return 1;
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}
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cat(fd);
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close(fd);
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}
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}
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return 0;
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}
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