72 lines
1.7 KiB
C
72 lines
1.7 KiB
C
/* tailit.c: Output the last part of files */
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#include "list.h"
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#include <stdbool.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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/* Functions */
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void usage(int status) {
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fprintf(stderr, "Usage: tailit [-n NUMBER]\n\n");
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fprintf(stderr, " -n NUMBER Output the last NUMBER of lines (default is 10)\n");
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exit(status);
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}
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List *tail_stream(FILE *stream, size_t limit) {
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List *sequence = list_create();
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char buffer[BUFSIZ];
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while (fgets(buffer, sizeof(buffer), stream) != NULL) {
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char *line = strdup(buffer);
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list_append(sequence, (Value){.string = line});
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// If over limit, remove the oldest line (head)
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if (sequence->size > limit) {
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Value old = list_pop(sequence, 0);
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free(old.string); // Free the popped line's string
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}
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}
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return sequence;
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}
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/* Main Execution */
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int main(int argc, char *argv[]) {
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size_t limit = 10; // Set baseline limit
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// TODO: Parse command line arguments
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if (argc == 2) {
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if (strcmp(argv[1], "-h") == 0) {
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usage(EXIT_SUCCESS);
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} else {
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usage(EXIT_FAILURE);
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}
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} else if (argc == 3) {
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if (strcmp(argv[1], "-n") == 0) {
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limit = (size_t)atoi(argv[2]);
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} else {
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usage(EXIT_FAILURE);
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}
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} else if (argc > 3) {
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usage(EXIT_FAILURE);
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}
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// TODO: Construct tail of stream
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List *lines = tail_stream(stdin, limit);
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// TODO: Print out tail
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while (lines->size > 0) {
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Value v = list_pop(lines, 0);
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printf("%s", v.string);
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free(v.string);
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}
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list_delete(lines, false);
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return EXIT_SUCCESS;
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}
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/* vim: set sts=4 sw=4 ts=8 expandtab ft=c: */
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