summaryrefslogtreecommitdiff
path: root/uniq.c
diff options
context:
space:
mode:
authorMatt Kraai2000-09-27 02:29:39 +0000
committerMatt Kraai2000-09-27 02:29:39 +0000
commite0bcce09baff576b1b16b3ffe780b6d91c7710c2 (patch)
tree69c78c69eaf5ad8e69f54f7c374f5ac3b2c5a950 /uniq.c
parent8ce85ce4e3595ac15d4746adc3b5c920fe4db1e8 (diff)
downloadbusybox-e0bcce09baff576b1b16b3ffe780b6d91c7710c2.zip
busybox-e0bcce09baff576b1b16b3ffe780b6d91c7710c2.tar.gz
Rewrote uniq to be less than a third of the size, and fixed some other
minor problems.
Diffstat (limited to 'uniq.c')
-rw-r--r--uniq.c160
1 files changed, 17 insertions, 143 deletions
diff --git a/uniq.c b/uniq.c
index ef38587..cfe6cca 100644
--- a/uniq.c
+++ b/uniq.c
@@ -5,6 +5,7 @@
*
* Copyright (C) 1999,2000 by Lineo, inc.
* Written by John Beppu <beppu@lineo.com>
+ * Rewritten by Matt Kraai <kraai@alumni.carnegiemellon.edu>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
@@ -27,156 +28,29 @@
#include <string.h>
#include <errno.h>
-/* max chars in line */
-#define UNIQ_MAX 4096
-
-typedef void (Print) (FILE *, const char *);
-
-typedef int (Decide) (const char *, const char *);
-
-/* container for two lines to be compared */
-typedef struct {
- char *a;
- char *b;
- int recurrence;
- FILE *in;
- FILE *out;
- void *func;
-} Subject;
-
-/* set up all the variables of a uniq operation */
-static Subject *subject_init(Subject * self, FILE * in, FILE * out,
- void *func)
-{
- self->a = NULL;
- self->b = NULL;
- self->in = in;
- self->out = out;
- self->func = func;
- self->recurrence = 0;
- return self;
-}
-
-/* point a and b to the appropriate lines;
- * count the recurrences (if any) of a string;
- */
-static Subject *subject_next(Subject * self)
-{
- /* tmp line holders */
- static char line[2][UNIQ_MAX];
- static int alternator = 0;
-
- if (fgets(line[alternator], UNIQ_MAX, self->in)) {
- self->a = self->b;
- self->b = line[alternator];
- alternator ^= 1;
- return self;
- }
-
- return NULL;
-}
-
-static Subject *subject_last(Subject * self)
-{
- self->a = self->b;
- self->b = NULL;
- return self;
-}
-
-static Subject *subject_study(Subject * self)
-{
- if (self->a == NULL) {
- return self;
- }
- if (self->b == NULL) {
- fprintf(self->out, "%s", self->a);
- return self;
- }
- if (strcmp(self->a, self->b) == 0) {
- self->recurrence++;
- } else {
- fprintf(self->out, "%s", self->a);
- self->recurrence = 0;
- }
- return self;
-}
-
-static int
-set_file_pointers(int schema, FILE ** in, FILE ** out, char **argv)
-{
- switch (schema) {
- case 0:
- *in = stdin;
- *out = stdout;
- break;
- case 1:
- *in = fopen(argv[0], "r");
- *out = stdout;
- break;
- case 2:
- *in = fopen(argv[0], "r");
- *out = fopen(argv[1], "w");
- break;
- }
- if (*in == NULL) {
- errorMsg("%s: %s\n", argv[0], strerror(errno));
- return errno;
- }
- if (*out == NULL) {
- errorMsg("%s: %s\n", argv[1], strerror(errno));
- return errno;
- }
- return 0;
-}
-
-
-/* one variable is the decision algo */
-/* another variable is the printing algo */
-
-/* I don't think I have to have more than a 1 line memory
- this is the one constant */
-
-/* it seems like GNU/uniq only takes one or two files as an option */
-
-/* ________________________________________________________________________ */
int uniq_main(int argc, char **argv)
{
- int i;
- char opt;
- FILE *in, *out;
- Subject s;
+ FILE *in = stdin, *out = stdout;
+ char *lastline = NULL, *input;
/* parse argv[] */
- for (i = 1; i < argc; i++) {
- if (argv[i][0] == '-') {
- opt = argv[i][1];
- switch (opt) {
- case '-':
- case 'h':
- usage(uniq_usage);
- default:
- usage(uniq_usage);
- }
- } else {
- break;
- }
- }
+ if ((argc > 1 && **(argv + 1) == '-') || argc > 3)
+ usage(uniq_usage);
- /* 0 src: stdin; dst: stdout */
- /* 1 src: file; dst: stdout */
- /* 2 src: file; dst: file */
- if (set_file_pointers((argc - 1), &in, &out, &argv[i])) {
- exit(1);
+ if (argv[1] != NULL) {
+ in = xfopen(argv[1], "r");
+ if (argv[2] != NULL)
+ out = xfopen(argv[2], "w");
}
- subject_init(&s, in, out, NULL);
- while (subject_next(&s)) {
- subject_study(&s);
+ while ((input = get_line_from_file(in)) != NULL) {
+ if (lastline == NULL || strcmp(input, lastline) != 0) {
+ fputs(input, out);
+ free(lastline);
+ lastline = input;
+ }
}
- subject_last(&s);
- subject_study(&s);
+ free(lastline);
- return(0);
+ return EXIT_SUCCESS;
}
-
-/* $Id: uniq.c,v 1.14 2000/09/25 21:45:58 andersen Exp $ */