1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
|
/* SPDX-License-Identifier: Apache-2.0 */
/* Copyright 2025 Thorsten Töpper
*
* I noticed GNU uniq -u not always removed all overlaps, instead
* of spending hours in creating a reproducable test case and code
* review, a simple custom implementation of that mode.
*
* vim:ts=4:sw=4:expandtab
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <stdbool.h>
#include <stdint.h>
#include <errno.h>
#include "trace_macros.h"
#define LINE_LENGTH 4096
/* prev=(cur)?0:1; less cycles? */
#define INDEXSWITCH cur=(cur+1)%2; prev=(prev+1)%2;
int main(int argc, char **argv) {
FILE *fdin = stdin;
char *lines[2];
int cur = 1, prev = 0;
bool duplicate = false;
if (argc > 1) {
if (strncmp(argv[1], "-", 2) != 0) {
if ((fdin=fopen(argv[1], "r")) == NULL) {
LOGERR("ERROR: Failed to open file %s: %s\n",
argv[1], strerror(errno));
return EXIT_FAILURE;
}
}
}
lines[0] = calloc(LINE_LENGTH, sizeof(char));
lines[1] = calloc(LINE_LENGTH, sizeof(char));
if (lines[0] == NULL || lines[1] == NULL) {
LOGERR("ERROR: Failed to allocate 8kiB...\n");
return EXIT_FAILURE;
}
/* preparation */
if (fgets(lines[prev], LINE_LENGTH, fdin) == NULL) {
LOGERR("ERROR: Failed to read input line.\n");
return EXIT_FAILURE;
}
/* parsing input */
while (fgets(lines[cur], LINE_LENGTH, fdin) != NULL) {
if (strcmp(lines[cur], lines[prev]) == 0) {
duplicate = true;
continue;
}
if ( ! duplicate ) {
fputs(lines[prev], stdout);
} else {
duplicate = false;
}
INDEXSWITCH;
}
/* last line */
if ( ! duplicate ) {
fputs(lines[prev], stdout);
}
if (fdin != stdin)
fclose(fdin);
return EXIT_SUCCESS;
}
|
