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#include "../command.h"
#include <stdio.h>
#include <string.h>
#include <sys/stat.h>
static void tail_file(FILE* file) {
char* ring[10];
memset(ring, 0, sizeof(char*) * 10);
int ring_len[10];
int index = 0;
int size = 0;
int read;
size_t len = 0;
char* line = NULL;
while ((read = getline(&line, &len, file)) != -1) {
if (ring[index] != NULL) free(ring[index]);
ring[index] = line;
ring_len[index] = read;
index++;
index %= 10;
if (size < 10) size++;
line = NULL;
}
index += 10 - size;
index %= 10;
for (int i = 0; i < size; i++) {
fwrite(ring[index], ring_len[index], 1, stdout);
free(ring[index]);
index += 1;
index %= 10;
}
free(line);
fclose(file);
}
static void help() {
printf("Usage: tail [FILE]...\n\n");
printf("Print last 10 lines of FILEs (or stdin) to.\n");
printf("With more than one FILE, precede each with a filename header.\n");
exit(EXIT_SUCCESS);
}
COMMAND(tail) {
if (argc < 1) {
tail_file(stdin);
return EXIT_SUCCESS;
}
if (streql(argv[0], "--help")) help();
if (argc == 1) {
FILE* file = get_file(argv[0], "r");
tail_file(file);
return EXIT_SUCCESS;
}
for (int i = 0; i < argc; i++) {
FILE* file;
if (streql("-", argv[i])) {
file = stdin;
} else {
file = get_file_s(argv[i], "r");
if (file == NULL) continue;
}
printf("\n==> %s <==\n", argv[i]);
tail_file(file);
}
return EXIT_SUCCESS;
}
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