(history.info.gz) History Programming Example

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(history.info.gz) History Variables

(history.info.gz) Programming with GNU History

 
 2.5 History Programming Example
 ===============================
 
 The following program demonstrates simple use of the GNU History
 Library.
 
      #include <stdio.h>
      #include <readline/history.h>
 
      main (argc, argv)
           int argc;
           char **argv;
      {
        char line[1024], *t;
        int len, done = 0;
 
        line[0] = 0;
 
        using_history ();
        while (!done)
          {
            printf ("history$ ");
            fflush (stdout);
            t = fgets (line, sizeof (line) - 1, stdin);
            if (t && *t)
              {
                len = strlen (t);
                if (t[len - 1] == '\n')
                  t[len - 1] = '\0';
              }
 
            if (!t)
              strcpy (line, "quit");
 
            if (line[0])
              {
                char *expansion;
                int result;
 
                result = history_expand (line, &expansion);
                if (result)
                  fprintf (stderr, "%s\n", expansion);
 
                if (result < 0 || result == 2)
                  {
                    free (expansion);
                    continue;
                  }
 
                add_history (expansion);
                strncpy (line, expansion, sizeof (line) - 1);
                free (expansion);
              }
 
            if (strcmp (line, "quit") == 0)
              done = 1;
            else if (strcmp (line, "save") == 0)
              write_history ("history_file");
            else if (strcmp (line, "read") == 0)
              read_history ("history_file");
            else if (strcmp (line, "list") == 0)
              {
                register HIST_ENTRY **the_list;
                register int i;
 
                the_list = history_list ();
                if (the_list)
                  for (i = 0; the_list[i]; i++)
                    printf ("%d: %s\n", i + history_base, the_list[i]->line);
              }
            else if (strncmp (line, "delete", 6) == 0)
              {
                int which;
                if ((sscanf (line + 6, "%d", &which)) == 1)
                  {
                    HIST_ENTRY *entry = remove_history (which);
                    if (!entry)
                      fprintf (stderr, "No such entry %d\n", which);
                    else
                      {
                        free (entry->line);
                        free (entry);
                      }
                  }
                else
                  {
                    fprintf (stderr, "non-numeric arg given to `delete'\n");
                  }
              }
          }
      }
 

Info Catalog

(history.info.gz) History Variables

(history.info.gz) Programming with GNU History