Edit
thodg/libiconv/tests/uniq-u.c
Bruno Haible
- tests/uniq-u.c
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/* uniq -- remove duplicate lines from a sorted file Copyright (C) 86, 91, 1995-1998, 1999 Free Software Foundation, Inc. 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 the Free Software Foundation; either version 2, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ /* Written by Richard Stallman and David MacKenzie. */ /* 2000-03-22 Trimmed down to the case of "uniq -u" by Bruno Haible. */ #include <stddef.h> #include <stdio.h> #include <stdlib.h> #include <string.h> /* The name this program was run with. */ static char *program_name; static void xalloc_fail (void) { fprintf (stderr, "%s: virtual memory exhausted\n", program_name); exit (1); } /* Allocate N bytes of memory dynamically, with error checking. */ void * xmalloc (size_t n) { void *p; p = malloc (n); if (p == 0) xalloc_fail (); return p; } /* Change the size of an allocated block of memory P to N bytes, with error checking. If P is NULL, run xmalloc. */ void * xrealloc (void *p, size_t n) { p = realloc (p, n); if (p == 0) xalloc_fail (); return p; } /* A `struct linebuffer' holds a line of text. */ struct linebuffer { size_t size; /* Allocated. */ size_t length; /* Used. */ char *buffer; }; /* Initialize linebuffer LINEBUFFER for use. */ static void initbuffer (struct linebuffer *linebuffer) { linebuffer->length = 0; linebuffer->size = 200; linebuffer->buffer = (char *) xmalloc (linebuffer->size); } /* Read an arbitrarily long line of text from STREAM into LINEBUFFER. Keep the newline; append a newline if it's the last line of a file that ends in a non-newline character. Do not null terminate. Return LINEBUFFER, except at end of file return 0. */ static struct linebuffer * readline (struct linebuffer *linebuffer, FILE *stream) { int c; char *buffer = linebuffer->buffer; char *p = linebuffer->buffer; char *end = buffer + linebuffer->size - 1; /* Sentinel. */ if (feof (stream) || ferror (stream)) return 0; do { c = getc (stream); if (c == EOF) { if (p == buffer) return 0; if (p[-1] == '\n') break; c = '\n'; } if (p == end) { linebuffer->size *= 2; buffer = (char *) xrealloc (buffer, linebuffer->size); p = p - linebuffer->buffer + buffer; linebuffer->buffer = buffer; end = buffer + linebuffer->size - 1; } *p++ = c; } while (c != '\n'); linebuffer->length = p - buffer; return linebuffer; } /* Free linebuffer LINEBUFFER's data. */ static void freebuffer (struct linebuffer *linebuffer) { free (linebuffer->buffer); } /* Undefine, to avoid warning about redefinition on some systems. */ #undef min #define min(x, y) ((x) < (y) ? (x) : (y)) /* Return zero if two strings OLD and NEW match, nonzero if not. OLD and NEW point not to the beginnings of the lines but rather to the beginnings of the fields to compare. OLDLEN and NEWLEN are their lengths. */ static int different (const char *old, const char *new, size_t oldlen, size_t newlen) { int order; order = memcmp (old, new, min (oldlen, newlen)); if (order == 0) return oldlen - newlen; return order; } /* Output the line in linebuffer LINE to stream STREAM provided that the switches say it should be output. If requested, print the number of times it occurred, as well; LINECOUNT + 1 is the number of times that the line occurred. */ static void writeline (const struct linebuffer *line, FILE *stream, int linecount) { if (linecount == 0) fwrite (line->buffer, 1, line->length, stream); } /* Process input file INFILE with output to OUTFILE. If either is "-", use the standard I/O stream for it instead. */ static void check_file (const char *infile, const char *outfile) { FILE *istream; FILE *ostream; struct linebuffer lb1, lb2; struct linebuffer *thisline, *prevline, *exch; char *prevfield, *thisfield; size_t prevlen, thislen; int match_count = 0; if (!strcmp (infile, "-")) istream = stdin; else istream = fopen (infile, "r"); if (istream == NULL) { fprintf (stderr, "%s: error opening %s\n", program_name, infile); exit (1); } if (!strcmp (outfile, "-")) ostream = stdout; else ostream = fopen (outfile, "w"); if (ostream == NULL) { fprintf (stderr, "%s: error opening %s\n", program_name, outfile); exit (1); } thisline = &lb1; prevline = &lb2; initbuffer (thisline); initbuffer (prevline); if (readline (prevline, istream) == 0) goto closefiles; prevfield = prevline->buffer; prevlen = prevline->length; while (!feof (istream)) { int match; if (readline (thisline, istream) == 0) break; thisfield = thisline->buffer; thislen = thisline->length; match = !different (thisfield, prevfield, thislen, prevlen); if (match) ++match_count; if (!match) { writeline (prevline, ostream, match_count); exch = prevline; prevline = thisline; thisline = exch; prevfield = thisfield; prevlen = thislen; if (!match) match_count = 0; } } writeline (prevline, ostream, match_count); closefiles: if (ferror (istream) || fclose (istream) == EOF) { fprintf (stderr, "%s: error reading %s\n", program_name, infile); exit (1); } if (ferror (ostream) || fclose (ostream) == EOF) { fprintf (stderr, "%s: error writing %s\n", program_name, outfile); exit (1); } freebuffer (&lb1); freebuffer (&lb2); } int main (int argc, char **argv) { const char *infile = "-"; const char *outfile = "-"; int optind = 1; program_name = argv[0]; if (optind < argc) infile = argv[optind++]; if (optind < argc) outfile = argv[optind++]; if (optind < argc) { fprintf (stderr, "%s: too many arguments\n", program_name); exit (1); } check_file (infile, outfile); exit (0); }