path: root/src/pacman/ini.c

/*
 *  ini.c
 *
 *  Copyright (c) 2013 Pacman Development Team <pacman-dev@archlinux.org>
 *
 *  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 of the License, 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, see <http://www.gnu.org/licenses/>.
 */

#include <errno.h>
#include <glob.h>
#include <limits.h>
#include <string.h> /* strdup */

#include <alpm.h>

#include "ini.h"
#include "util.h"

static const int ini_max_recursion = 10;

/**
 * @brief INI parser backend.
 *
 * @param file path to the config file
 * @param cb callback for key/value pairs
 * @param data caller defined data to be passed to the callback
 * @param section_name the name of the current section
 * @param line buffer to read into, must be at least PATH_MAX long
 * @param depth recursion depth, should initially be 0
 *
 * @return 0 on success, 1 on parsing errors, the callback return value
 * otherwise
 */
static int _parse_ini(const char *file, ini_parser_fn cb, void *data,
    char **section_name, char *line, int depth)
{
  FILE *fp = NULL;
  int linenum = 0;
  int ret = 0;

  if(depth >= ini_max_recursion) {
    pm_printf(ALPM_LOG_ERROR,
        _("config parsing exceeded max recursion depth of %d.\n"),
        ini_max_recursion);
    ret = 1;
    goto cleanup;
  }

  pm_printf(ALPM_LOG_DEBUG, "config: attempting to read file %s\n", file);
  fp = fopen(file, "r");
  if(fp == NULL) {
    pm_printf(ALPM_LOG_ERROR, _("config file %s could not be read: %s\n"),
        file, strerror(errno));
    ret = 1;
    goto cleanup;
  }

  while(fgets(line, PATH_MAX, fp)) {
    char *key, *value, *ptr;
    size_t line_len;

    linenum++;

    /* ignore whole line and end of line comments */
    if((ptr = strchr(line, '#'))) {
      *ptr = '\0';
    }

    line_len = strtrim(line);

    if(line_len == 0) {
      continue;
    }

    if(line[0] == '[' && line[line_len - 1] == ']') {
      char *name;
      /* only possibility here is a line == '[]' */
      if(line_len <= 2) {
        pm_printf(ALPM_LOG_ERROR, _("config file %s, line %d: bad section name.\n"),
            file, linenum);
        ret = 1;
        goto cleanup;
      }
      /* new config section, skip the '[' */
      name = strdup(line + 1);
      name[line_len - 2] = '\0';

      ret = cb(file, linenum, name, NULL, NULL, data);
      free(*section_name);
      *section_name = name;

      /* we're at a new section; perform any post-actions for the prior */
      if(ret) {
        goto cleanup;
      }
      continue;
    }

    /* directive */
    /* strsep modifies the 'line' string: 'key \0 value' */
    key = line;
    value = line;
    strsep(&value, "=");
    strtrim(key);
    strtrim(value);

    if(key == NULL) {
      pm_printf(ALPM_LOG_ERROR, _("config file %s, line %d: syntax error in config file- missing key.\n"),
          file, linenum);
      ret = 1;
      goto cleanup;
    }
    /* Include is allowed in both options and repo sections */
    if(strcmp(key, "Include") == 0) {
      glob_t globbuf;
      int globret;
      size_t gindex;

      if(value == NULL) {
        pm_printf(ALPM_LOG_ERROR, _("config file %s, line %d: directive '%s' needs a value\n"),
            file, linenum, key);
        ret = 1;
        goto cleanup;
      }
      /* Ignore include failures... assume non-critical */
      globret = glob(value, GLOB_NOCHECK, NULL, &globbuf);
      switch(globret) {
        case GLOB_NOSPACE:
          pm_printf(ALPM_LOG_DEBUG,
              "config file %s, line %d: include globbing out of space\n",
              file, linenum);
          break;
        case GLOB_ABORTED:
          pm_printf(ALPM_LOG_DEBUG,
              "config file %s, line %d: include globbing read error for %s\n",
              file, linenum, value);
          break;
        case GLOB_NOMATCH:
          pm_printf(ALPM_LOG_DEBUG,
              "config file %s, line %d: no include found for %s\n",
              file, linenum, value);
          break;
        default:
          for(gindex = 0; gindex < globbuf.gl_pathc; gindex++) {
            pm_printf(ALPM_LOG_DEBUG, "config file %s, line %d: including %s\n",
                file, linenum, globbuf.gl_pathv[gindex]);
            ret =_parse_ini(globbuf.gl_pathv[gindex], cb, data,
                section_name, line, depth + 1);
            if(ret) {
              globfree(&globbuf);
              goto cleanup;
            }
          }
          break;
      }
      globfree(&globbuf);
      continue;
    }
    if((ret = cb(file, linenum, *section_name, key, value, data)) != 0) {
      goto cleanup;
    }
  }

  if(depth == 0) {
    ret = cb(NULL, 0, NULL, NULL, NULL, data);
  }

cleanup:
  if(fp) {
    fclose(fp);
  }
  if(depth == 0) {
    free(*section_name);
    *section_name = NULL;
  }
  pm_printf(ALPM_LOG_DEBUG, "config: finished parsing %s\n", file);
  return ret;
}

/**
 * @brief Parse a pacman-style INI config file.
 *
 * @param file path to the config file
 * @param cb callback for key/value pairs
 * @param data caller defined data to be passed to the callback
 *
 * @return 0 on success, 1 on parsing errors, the callback return value
 * otherwise
 *
 * @note The callback will be called at the beginning of each section with an
 * empty key and value, for each key/value pair, and when parsing is complete
 * with all arguments except @a data empty.
 *
 * @note The @a key and @a value passed to @ cb will be overwritten between
 * calls.  The section name will remain valid until after @a cb is called to
 * begin a new section.
 *
 * @note Parsing will immediately stop if the callback returns non-zero.
 */
int parse_ini(const char *file, ini_parser_fn cb, void *data)
{
  char *section_name = NULL, line[PATH_MAX];
  return _parse_ini(file, cb, data, &section_name, line, 0);
}

/* vim: set ts=2 sw=2 noet: */