getty: fix for NOCTTY killing us with SIGHUP
[oweals/busybox.git] / coreutils / uniq.c
index a7caef991ca74051821dc228b448a7010f9c6a66..9208d34ec487040bf3a7c40394f910cfe618367e 100644 (file)
  *
  * Copyright (C) 2005  Manuel Novoa III  <mjn3@codepoet.org>
  *
- * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
  */
 
 /* BB_AUDIT SUSv3 compliant */
 /* http://www.opengroup.org/onlinepubs/007904975/utilities/uniq.html */
 
-#include "libbb.h"
-
-static const char uniq_opts[] ALIGN1 = "cdu" "f:s:" "cdu\0\1\2\4";
-
-static FILE *xgetoptfile_uniq_s(char **argv, int read0write2)
-{
-       const char *n;
+//usage:#define uniq_trivial_usage
+//usage:       "[-cdu][-f,s,w N] [INPUT [OUTPUT]]"
+//usage:#define uniq_full_usage "\n\n"
+//usage:       "Discard duplicate lines\n"
+//usage:     "\n       -c      Prefix lines by the number of occurrences"
+//usage:     "\n       -d      Only print duplicate lines"
+//usage:     "\n       -u      Only print unique lines"
+//usage:     "\n       -f N    Skip first N fields"
+//usage:     "\n       -s N    Skip first N chars (after any skipped fields)"
+//usage:     "\n       -w N    Compare N characters in line"
+//usage:
+//usage:#define uniq_example_usage
+//usage:       "$ echo -e \"a\\na\\nb\\nc\\nc\\na\" | sort | uniq\n"
+//usage:       "a\n"
+//usage:       "b\n"
+//usage:       "c\n"
 
-       n = *argv;
-       if (n != NULL) {
-               if ((*n != '-') || n[1]) {
-                       return xfopen(n, "r\0w" + read0write2);
-               }
-       }
-       return (read0write2) ? stdout : stdin;
-}
+#include "libbb.h"
 
-int uniq_main(int argc, char **argv);
-int uniq_main(int argc, char **argv)
+int uniq_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int uniq_main(int argc UNUSED_PARAM, char **argv)
 {
-       FILE *in, *out;
-       unsigned long dups, skip_fields, skip_chars, i;
-       const char *s0, *e0, *s1, *e1, *input_filename;
+       const char *input_filename;
+       unsigned skip_fields, skip_chars, max_chars;
        unsigned opt;
+       char *cur_line;
+       const char *cur_compare;
 
        enum {
                OPT_c = 0x1,
-               OPT_d = 0x2,
-               OPT_u = 0x4,
+               OPT_d = 0x2, /* print only dups */
+               OPT_u = 0x4, /* print only uniq */
                OPT_f = 0x8,
                OPT_s = 0x10,
+               OPT_w = 0x20,
        };
 
        skip_fields = skip_chars = 0;
+       max_chars = INT_MAX;
 
-       opt = getopt32(argc, argv, "cduf:s:", &s0, &s1);
-       if (opt & OPT_f)
-               skip_fields = xatoul(s0);
-       if (opt & OPT_s)
-               skip_chars = xatoul(s1);
+       opt_complementary = "f+:s+:w+";
+       opt = getopt32(argv, "cduf:s:w:", &skip_fields, &skip_chars, &max_chars);
        argv += optind;
 
-       input_filename = *argv;
+       input_filename = argv[0];
+       if (input_filename) {
+               const char *output;
 
-       in = xgetoptfile_uniq_s(argv, 0);
-       if (*argv) {
-               ++argv;
-       }
-       out = xgetoptfile_uniq_s(argv, 2);
-       if (*argv && argv[1]) {
-               bb_show_usage();
+               if (input_filename[0] != '-' || input_filename[1]) {
+                       close(STDIN_FILENO); /* == 0 */
+                       xopen(input_filename, O_RDONLY); /* fd will be 0 */
+               }
+               output = argv[1];
+               if (output) {
+                       if (argv[2])
+                               bb_show_usage();
+                       if (output[0] != '-' || output[1]) {
+                               // Won't work with "uniq - FILE" and closed stdin:
+                               //close(STDOUT_FILENO);
+                               //xopen(output, O_WRONLY | O_CREAT | O_TRUNC);
+                               xmove_fd(xopen(output, O_WRONLY | O_CREAT | O_TRUNC), STDOUT_FILENO);
+                       }
+               }
        }
 
-       s1 = e1 = NULL;                         /* prime the pump */
+       cur_compare = cur_line = NULL; /* prime the pump */
 
        do {
-               s0 = s1;
-               e0 = e1;
+               unsigned i;
+               unsigned long dups;
+               char *old_line;
+               const char *old_compare;
+
+               old_line = cur_line;
+               old_compare = cur_compare;
                dups = 0;
 
                /* gnu uniq ignores newlines */
-               while ((s1 = xmalloc_getline(in)) != NULL) {
-                       e1 = s1;
+               while ((cur_line = xmalloc_fgetline(stdin)) != NULL) {
+                       cur_compare = cur_line;
                        for (i = skip_fields; i; i--) {
-                               e1 = skip_whitespace(e1);
-                               e1 = skip_non_whitespace(e1);
+                               cur_compare = skip_whitespace(cur_compare);
+                               cur_compare = skip_non_whitespace(cur_compare);
                        }
-                       for (i = skip_chars; *e1 && i; i--) {
-                               ++e1;
+                       for (i = skip_chars; *cur_compare && i; i--) {
+                               ++cur_compare;
                        }
 
-                       if (!s0 || strcmp(e0, e1)) {
+                       if (!old_line || strncmp(old_compare, cur_compare, max_chars)) {
                                break;
                        }
 
-                       ++dups;          /* Note: Testing for overflow seems excessive. */
+                       free(cur_line);
+                       ++dups;  /* testing for overflow seems excessive */
                }
 
-               if (s0) {
-                       if (!(opt & (OPT_d << !!dups))) { /* (if dups, opt & OPT_e) */
-                               fprintf(out, "\0%d " + (opt & 1), dups + 1);
-                               fprintf(out, "%s\n", s0);
+               if (old_line) {
+                       if (!(opt & (OPT_d << !!dups))) { /* (if dups, opt & OPT_u) */
+                               if (opt & OPT_c) {
+                                       /* %7lu matches GNU coreutils 6.9 */
+                                       printf("%7lu ", dups + 1);
+                               }
+                               printf("%s\n", old_line);
                        }
-                       free((void *)s0);
+                       free(old_line);
                }
-       } while (s1);
+       } while (cur_line);
 
-       die_if_ferror(in, input_filename);
+       die_if_ferror(stdin, input_filename);
 
        fflush_stdout_and_exit(EXIT_SUCCESS);
 }