findutils/grep.c

   1 /*
   2  * Copyright (c) 1999 by David I. Bell
   3  * Permission is granted to use, distribute, or modify this source,
   4  * provided that this copyright notice remains intact.
   5  *
   6  * The "grep" command, taken from sash.
   7  * This provides basic file searching.
   8  *
   9  * Permission to distribute this code under the GPL has been granted.
  10  * Modified for busybox by Erik Andersen <andersee@debian.org> <andersen@lineo.com>
  11  */
  12
  13 #include "internal.h"
  14 #ifdef BB_GREP
  15
  16 #include <stdio.h>
  17 #include <dirent.h>
  18 #include <errno.h>
  19 #include <fcntl.h>
  20 #include <signal.h>
  21 #include <time.h>
  22 #include <ctype.h>
  23
  24
  25 const char grep_usage[] =
  26 "Search the input file(s) for lines matching the given pattern.\n"
  27 "\tI search stdin if no files are given.\n"
  28 "\tI can't grok full regular expressions.\n"
  29 "usage: grep [in] PATTERN [FILES]...\n"
  30 "\ti=ignore case, n=list line numbers\n";
  31
  32
  33
  34 static  BOOL    search
  35         (const char * string, const char * word, BOOL ignoreCase);
  36
  37
  38 extern int
  39 grep_main(int argc, char ** argv)
  40 {
  41         FILE *          fp;
  42         const char *    word;
  43         const char *    name;
  44         const char *    cp;
  45         BOOL            tellName;
  46         BOOL            ignoreCase;
  47         BOOL            tellLine;
  48         long            line;
  49         char            buf[BUF_SIZE];
  50
  51         ignoreCase = FALSE;
  52         tellLine = FALSE;
  53
  54         argc--;
  55         argv++;
  56         if (argc < 1)
  57         {
  58                 fprintf(stderr, "%s", grep_usage);
  59                 return 1;
  60         }
  61
  62         if (**argv == '-')
  63         {
  64                 argc--;
  65                 cp = *argv++;
  66
  67                 while (*++cp) switch (*cp)
  68                 {
  69                         case 'i':
  70                                 ignoreCase = TRUE;
  71                                 break;
  72
  73                         case 'n':
  74                                 tellLine = TRUE;
  75                                 break;
  76
  77                         default:
  78                                 fprintf(stderr, "Unknown option\n");
  79                                 return 1;
  80                 }
  81         }
  82
  83         word = *argv++;
  84         argc--;
  85
  86         tellName = (argc > 1);
  87
  88         while (argc-- > 0)
  89         {
  90                 name = *argv++;
  91
  92                 fp = fopen(name, "r");
  93
  94                 if (fp == NULL)
  95                 {
  96                         perror(name);
  97
  98                         continue;
  99                 }
 100
 101                 line = 0;
 102
 103                 while (fgets(buf, sizeof(buf), fp))
 104                 {
 105                         line++;
 106
 107                         cp = &buf[strlen(buf) - 1];
 108
 109                         if (*cp != '\n')
 110                                 fprintf(stderr, "%s: Line too long\n", name);
 111
 112                         if (search(buf, word, ignoreCase))
 113                         {
 114                                 if (tellName)
 115                                         printf("%s: ", name);
 116
 117                                 if (tellLine)
 118                                         printf("%ld: ", line);
 119
 120                                 fputs(buf, stdout);
 121                         }
 122                 }
 123
 124                 if (ferror(fp))
 125                         perror(name);
 126
 127                 fclose(fp);
 128         }
 129         return 0;
 130 }
 131
 132
 133 /*
 134  * See if the specified word is found in the specified string.
 135  */
 136 static BOOL
 137 search(const char * string, const char * word, BOOL ignoreCase)
 138 {
 139         const char *    cp1;
 140         const char *    cp2;
 141         int             len;
 142         int             lowFirst;
 143         int             ch1;
 144         int             ch2;
 145
 146         len = strlen(word);
 147
 148         if (!ignoreCase)
 149         {
 150                 while (TRUE)
 151                 {
 152                         string = strchr(string, word[0]);
 153
 154                         if (string == NULL)
 155                                 return FALSE;
 156
 157                         if (memcmp(string, word, len) == 0)
 158                                 return TRUE;
 159
 160                         string++;
 161                 }
 162         }
 163
 164         /*
 165          * Here if we need to check case independence.
 166          * Do the search by lower casing both strings.
 167          */
 168         lowFirst = *word;
 169
 170         if (isupper(lowFirst))
 171                 lowFirst = tolower(lowFirst);
 172
 173         while (TRUE)
 174         {
 175                 while (*string && (*string != lowFirst) &&
 176                         (!isupper(*string) || (tolower(*string) != lowFirst)))
 177                 {
 178                         string++;
 179                 }
 180
 181                 if (*string == '\0')
 182                         return FALSE;
 183
 184                 cp1 = string;
 185                 cp2 = word;
 186
 187                 do
 188                 {
 189                         if (*cp2 == '\0')
 190                                 return TRUE;
 191
 192                         ch1 = *cp1++;
 193
 194                         if (isupper(ch1))
 195                                 ch1 = tolower(ch1);
 196
 197                         ch2 = *cp2++;
 198
 199                         if (isupper(ch2))
 200                                 ch2 = tolower(ch2);
 201
 202                 }
 203                 while (ch1 == ch2);
 204
 205                 string++;
 206         }
 207 }
 208
 209 #endif
 210 /* END CODE */