Function feHelp

Singular/fehelp.cc:90–176

 *****************************************************************/
EXTERN_VAR BOOLEAN FE_OPT_NO_SHELL_FLAG;
void feHelp(char *str)
{
  str = strclean(str);
  if (str == NULL) {heBrowserHelp(NULL); return;}

  if (strlen(str) > MAX_HE_ENTRY_LENGTH - 2)  // need room for extra **
    str[MAX_HE_ENTRY_LENGTH - 3] = '\0';

  BOOLEAN key_is_regexp = (strchr(str, '*') != NULL);


  heEntry_s hentry;
  memset(&hentry,0,sizeof(hentry));
  char* idxfile = feResource('x' /*"IdxFile"*/);

  // Try exact match of help string with key in index
  if (!key_is_regexp && (idxfile != NULL) && heKey2Entry(idxfile, str, &hentry))
  {
    heBrowserHelp(&hentry);
    return;
  }

  // Try to match approximately with key in index file
  if (idxfile != NULL)
  {
    if (heCurrentHelpBrowser == NULL) feHelpBrowser(NULL, 0);
    assume(heCurrentHelpBrowser != NULL);

    StringSetS("");
    int found = heReKey2Entry(idxfile, str, &hentry);


    if (found == 0)
    {
      // try proc help and library help
      if (! key_is_regexp && heOnlineHelp(str)) return;

      // Try to match with str*
      char mkey[MAX_HE_ENTRY_LENGTH];
      strcpy(mkey, str);
      strcat(mkey, "*");
      found = heReKey2Entry(idxfile, mkey, &hentry);
      // Try to match with *str*
      if (found == 0)
      {
        mkey[0] = '*';
        strcpy(mkey + 1, str);
        strcat(mkey, "*");
        found = heReKey2Entry(idxfile, mkey, &hentry);
      }

      // Print warning and return if nothing found
      if (found == 0)
      {
        Warn("No help for topic '%s' (not even for '*%s*')", str, str);
        WarnS("Try '?;'       for general help");
        WarnS("or  '?Index;'  for all available help topics.");
        return;