devspec.en_US/project/recutils/utils/recfmt.c

   1 /* -*- mode: C -*-
   2  *
   3  *       File:         recfmt.c
   4  *       Date:         Wed Dec 22 18:20:20 2010
   5  *
   6  *       GNU recutils - recfmt
   7  *
   8  */
   9
  10 /* Copyright (C) 2010-2019 Jose E. Marchesi */
  11
  12 /* This program is free software: you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License as published by
  14  * the Free Software Foundation, either version 3 of the License, or
  15  * (at your option) any later version.
  16  *
  17  * This program is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  * GNU General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU General Public License
  23  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  24  */
  25
  26 #include <config.h>
  27
  28 #include <string.h>
  29 #include <getopt.h>
  30 #include <stdlib.h>
  31 #include <xalloc.h>
  32 #include <regex.h>
  33 #include <gettext.h>
  34 #define _(str) gettext (str)
  35
  36 #include <rec.h>
  37 #include <recutl.h>
  38
  39 /* Forward prototypes.  */
  40 void recfmt_parse_args (int argc, char **argv);
  41 bool recfmt_process_data (rec_db_t db);
  42 void recfmt_process_db (rec_db_t db, char *template);
  43 char *recfmt_apply_template (rec_record_t record, char *template);
  44 char *recfmt_get_subst (rec_record_t record, char *str);
  45
  46 /*
  47  * Global variables
  48  */
  49
  50 char *recfmt_template = NULL;
  51
  52 /*
  53  * Command line options management.
  54  */
  55
  56 enum
  57 {
  58   COMMON_ARGS,
  59   FILE_ARG
  60 };
  61
  62 static const struct option GNU_longOptions[] =
  63   {
  64     COMMON_LONG_ARGS,
  65     {"file", required_argument, NULL, FILE_ARG},
  66     {NULL, 0, NULL, 0}
  67   };
  68
  69 /*
  70  * Functions.
  71  */
  72
  73 void
  74 recutl_print_help (void)
  75 {
  76   /* TRANSLATORS: --help output, recfmt synopsis.
  77      no-wrap */
  78   printf (_("\
  79 Usage: recfmt [OPTION]... [TEMPLATE]\n"));
  80
  81   /* TRANSLATORS: --help output, recfmt arguments.
  82      no-wrap */
  83   fputs(_("\
  84 Apply a template to records read from standard input.\n"), stdout);
  85
  86   puts ("");
  87   /* TRANSLATORS: --help output, recfmt arguments.
  88      no-wrap */
  89   fputs(_("\
  90   -f, --file=FILENAME                 read the template to apply from a file.\n"),
  91         stdout);
  92
  93   recutl_print_help_common ();
  94   puts ("");
  95   recutl_print_help_footer ();
  96 }
  97
  98 void
  99 recfmt_parse_args (int argc,
 100                    char **argv)
 101 {
 102   char c;
 103   int ret;
 104
 105   while ((ret = getopt_long (argc,
 106                              argv,
 107                              "f:",
 108                              GNU_longOptions,
 109                              NULL)) != -1)
 110     {
 111       c = ret;
 112       switch (c)
 113         {
 114           COMMON_ARGS_CASES
 115         case FILE_ARG:
 116         case 'f':
 117           {
 118             /* Read the template from the specified file and store it
 119                in recfmt_template.  */
 120             recfmt_template = recutl_read_file (optarg);
 121             if (!recfmt_template)
 122               {
 123                 recutl_fatal (_("can't open file %s for reading.\n"),
 124                               optarg);
 125               }
 126
 127             break;
 128           }
 129         default:
 130           {
 131             exit (EXIT_FAILURE);
 132           }
 133         }
 134     }
 135
 136   /* See if the template is specified in the command line.  */
 137   if (optind < argc)
 138     {
 139       if (recfmt_template)
 140         {
 141           recutl_fatal (_("don't specify a template in the command line and -f at the same time.\n"));
 142         }
 143
 144       if ((argc - optind) != 1)
 145         {
 146           recutl_print_help ();
 147           exit (EXIT_FAILURE);
 148         }
 149
 150       recfmt_template = xstrdup (argv[optind++]);
 151     }
 152 }
 153
 154 char *
 155 recfmt_get_subst (rec_record_t record,
 156                   char *str)
 157 {
 158   char *res;
 159   rec_sex_t sex;
 160
 161   sex = rec_sex_new (false);
 162   if (!rec_sex_compile (sex, str))
 163     {
 164       recutl_fatal (_("invalid expression in a template slot.\n"));
 165     }
 166
 167   res = rec_sex_eval_str (sex, record);
 168   if (!res)
 169     {
 170       recutl_fatal (_("error evaluating expression in a template slot.\n"));
 171     }
 172
 173   rec_sex_destroy (sex);
 174
 175   return res;
 176 }
 177
 178 char *
 179 recfmt_apply_template (rec_record_t record,
 180                        char *template)
 181 {
 182   rec_buf_t result_buf;
 183   char *result;
 184   char *tmp;
 185   size_t tmp_size;
 186   size_t result_size;
 187   char *p;
 188   regex_t regexp;
 189   regmatch_t matches;
 190   char *subst_str;
 191
 192   /* Replace occurrences of:
 193
 194      {{Name[N]}}
 195
 196      where Name[N] is the name of a field with an optional subscript.
 197      If the subscript is not present then it is assumed to be 0.  If
 198      the contents between {{...}} are not a field name then replace the
 199      slot with the empty string.
 200   */
 201
 202   if (regcomp (&regexp, "\\{\\{" "[^}]*" "\\}\\}", REG_EXTENDED) != 0)
 203     {
 204       recutl_fatal (_("recfmt_apply_template: error compiling regexp. Please report this.\n"));
 205     }
 206
 207   result_buf = rec_buf_new (&result, &result_size);
 208   p = template;
 209   while (*p
 210          && (regexec (&regexp, p, 1, &matches, 0) == 0)
 211          && (matches.rm_so != -1))
 212     {
 213       /* Add the prolog, if any.  */
 214       if (matches.rm_so > 0)
 215         {
 216           tmp = xmalloc (matches.rm_so + 1);
 217           memcpy (tmp, p, matches.rm_so);
 218           tmp[matches.rm_so] = '\0';
 219           rec_buf_puts (tmp, result_buf);
 220           free (tmp);
 221         }
 222
 223       /* Get the match.  */
 224       tmp_size = matches.rm_eo - matches.rm_so - 4;
 225       tmp = xmalloc (tmp_size + 1);
 226       memcpy (tmp, p + matches.rm_so + 2, tmp_size);
 227       tmp[tmp_size] = '\0';
 228
 229       /* Advance p. */
 230       p = p + matches.rm_eo;
 231
 232       /* Get the substitution text and append it to the result.  */
 233       subst_str = recfmt_get_subst (record, tmp);
 234       if (subst_str)
 235         {
 236           rec_buf_puts (subst_str, result_buf);
 237           free (subst_str);
 238         }
 239       free (tmp);
 240     }
 241
 242   /* Add the epilog, if any.  */
 243   if (*p)
 244     {
 245       rec_buf_puts (p, result_buf);
 246     }
 247
 248   rec_buf_close (result_buf);
 249
 250   return result;
 251 }
 252
 253 void
 254 recfmt_process_db (rec_db_t db, char *template)
 255 {
 256   size_t n_rset;
 257   rec_rset_t rset;
 258   rec_record_t record;
 259   char *result;
 260   rec_mset_iterator_t iter;
 261
 262   /* Iterate on all the record sets.  */
 263   for (n_rset = 0; n_rset < rec_db_size (db); n_rset++)
 264     {
 265       rset = rec_db_get_rset (db, n_rset);
 266
 267       /* Iterate on all the records.  */
 268
 269       iter = rec_mset_iterator (rec_rset_mset (rset));
 270       while (rec_mset_iterator_next (&iter, MSET_RECORD, (const void**) &record, NULL))
 271         {
 272           /* Apply the template to this record.  */
 273           result = recfmt_apply_template (record, template);
 274           if (result && (*result != '\0'))
 275             {
 276               printf ("%s", result);
 277               free (result);
 278             }
 279         }
 280
 281       rec_mset_iterator_free (&iter);
 282     }
 283 }
 284
 285 int
 286 main (int argc, char *argv[])
 287 {
 288   rec_db_t db;
 289
 290   recutl_init ("recfmt");
 291
 292   recfmt_parse_args (argc, argv);
 293
 294   db = recutl_read_db_from_file (NULL);
 295   if (db && recfmt_template)
 296     {
 297       recfmt_process_db (db, recfmt_template);
 298     }
 299
 300   return EXIT_SUCCESS;
 301 }
 302
 303 /* End of recfmt.c */