c/readline.c

   1 #include <stdlib.h>
   2 #include <stdio.h>
   3 #include <unistd.h>
   4
   5 #if USE_READLINE
   6   #include <readline/readline.h>
   7   #include <readline/history.h>
   8   #include <readline/tilde.h>
   9 #else
  10   #include <editline/readline.h>
  11 #endif
  12
  13 int history_loaded = 0;
  14
  15 char HISTORY_FILE[] = "~/.mal-history";
  16
  17 void load_history() {
  18     if (history_loaded) { return; }
  19     int ret;
  20     char *hf = tilde_expand(HISTORY_FILE);
  21     if (access(hf, F_OK) != -1) {
  22         // TODO: check if file exists first, use non-static path
  23 #if USE_READLINE
  24         ret = read_history(hf);
  25 #else
  26         FILE *fp = fopen(hf, "r");
  27         char *line = malloc(80); // getline reallocs as necessary
  28         size_t sz = 80;
  29         while ((ret = getline(&line, &sz, fp)) > 0) {
  30             add_history(line); // Add line to in-memory history
  31         }
  32         free(line);
  33         fclose(fp);
  34 #endif
  35         history_loaded = 1;
  36     }
  37     free(hf);
  38 }
  39
  40 void append_to_history() {
  41     char *hf = tilde_expand(HISTORY_FILE);
  42 #ifdef USE_READLINE
  43     append_history(1, hf);
  44 #else
  45     HIST_ENTRY *he = history_get(history_base+history_length-1);
  46     FILE *fp = fopen(hf, "a");
  47     if (fp) {
  48         fprintf(fp, "%s\n", he->line);
  49         fclose(fp);
  50     }
  51 #endif
  52     free(hf);
  53 }
  54
  55
  56 // line must be freed by caller
  57 char *_readline (char prompt[]) {
  58     char *line;
  59
  60     load_history();
  61
  62     line = readline(prompt);
  63     if (!line) return NULL; // EOF
  64     add_history(line); // Add input to in-memory history
  65
  66     append_to_history(); // Flush new line of history to disk
  67
  68     return line;
  69 }
  70