NSString_RegEx.m

   1 //
   2 //  NSString_RegEx.m
   3 //
   4 //  Created by John R Chang on 2005-11-08.
   5 //  This code is Creative Commons Public Domain.  You may use it for any purpose whatsoever.
   6 //  http://creativecommons.org/licenses/publicdomain/
   7 //
   8
   9 #import "NSString_RegEx.h"
  10 #include <regex.h>
  11
  12
  13 @implementation NSString (RegEx)
  14
  15 - (NSArray *) substringsMatchingRegularExpression:(NSString *)pattern count:(int)nmatch options:(int)options ranges:(NSArray **)ranges error:(NSError **)error
  16 {
  17         options |= REG_EXTENDED;
  18         if (error)
  19                 *error = nil;
  20
  21         int errcode = 0;
  22         regex_t preg;
  23         regmatch_t * pmatch = NULL;
  24         NSMutableArray * outMatches = nil;
  25
  26         // Compile the regular expression
  27         errcode = regcomp(&preg, [pattern UTF8String], options);
  28         if (errcode != 0)
  29                 goto catch_error;       // regcomp error
  30
  31         // Match the regular expression against substring self
  32         pmatch = calloc(sizeof(regmatch_t), nmatch+1);
  33         errcode = regexec(&preg, [self UTF8String], (nmatch<0 ? 0 : nmatch+1), pmatch, 0);
  34
  35         /*if (errcode == REG_NOMATCH)
  36         {
  37                 outMatches = [NSMutableArray array];
  38                 goto catch_exit;        // no match
  39         }*/
  40         if (errcode != 0)
  41                 goto catch_error;       // regexec error
  42
  43         if (nmatch == -1)
  44         {
  45                 outMatches = [NSArray arrayWithObject:self];
  46                 goto catch_exit;        // simple match
  47         }
  48
  49         // Iterate through pmatch
  50         outMatches = [NSMutableArray array];
  51         if (ranges)
  52                 *ranges = [NSMutableArray array];
  53         int i;
  54         for (i=0; i<nmatch+1; i++)
  55         {
  56                 if (pmatch[i].rm_so == -1 || pmatch[i].rm_eo == -1)
  57                         break;
  58
  59                 NSRange range = NSMakeRange(pmatch[i].rm_so, pmatch[i].rm_eo - pmatch[i].rm_so);
  60                 NSString * substring = [[[NSString alloc] initWithBytes:[self UTF8String] + range.location
  61                                                                                                                  length:range.length
  62                                                                                                            encoding:NSUTF8StringEncoding] autorelease];
  63                 [outMatches addObject:substring];
  64
  65                 if (ranges)
  66                 {
  67                         NSValue * value = [NSValue valueWithRange:range];
  68                         [(NSMutableArray *)*ranges addObject:value];
  69                 }
  70         }
  71
  72 catch_error:
  73         if (errcode != 0 && error)
  74         {
  75                 // Construct error object
  76                 NSMutableDictionary * userInfo = [NSMutableDictionary dictionary];
  77                 char errbuf[256];
  78                 int len = regerror(errcode, &preg, errbuf, sizeof(errbuf));
  79                 if (len > 0)
  80                         [userInfo setObject:[NSString stringWithUTF8String:errbuf] forKey:NSLocalizedDescriptionKey];
  81                 *error = [NSError errorWithDomain:@"regerror" code:errcode userInfo:userInfo];
  82         }
  83
  84 catch_exit:
  85         if (pmatch)
  86                 free(pmatch);
  87         regfree(&preg);
  88         return outMatches;
  89 }
  90
  91 - (BOOL) grep:(NSString *)pattern options:(int)options
  92 {
  93         NSArray * substrings = [self substringsMatchingRegularExpression:pattern count:-1 options:options ranges:NULL error:NULL];
  94         return (substrings && [substrings count] > 0);
  95 }
  96
  97 @end