diplodocus.org Git - nmh/blob - sbr/read_switch_multiword_via_readline.c

   1 /* read_switch_multiword_via_readline.c -- get an answer from the user, with readline
   2  *
   3  * This code is Copyright (c) 2012, by the authors of nmh.  See the
   4  * COPYRIGHT file in the root directory of the nmh distribution for
   5  * complete copyright information.
   6  */
   7
   8 #include <h/mh.h>
   9
  10 #ifdef READLINE_SUPPORT
  11 #include <readline/readline.h>
  12 #include <readline/history.h>
  13
  14 static struct swit *rl_cmds;
  15
  16 static char *nmh_command_generator(const char *, int);
  17 static char **nmh_completion(const char *, int, int);
  18 static void initialize_readline(void);
  19
  20 static char ansbuf[BUFSIZ];
  21
  22 /*
  23  * getans, but with readline support
  24  */
  25
  26 char **
  27 read_switch_multiword_via_readline(char *prompt, struct swit *ansp)
  28 {
  29     char *ans, **cpp;
  30
  31     initialize_readline();
  32     rl_cmds = ansp;
  33
  34     for (;;) {
  35         ans = readline(prompt);
  36         /*
  37          * If we get an EOF, return
  38          */
  39
  40         if (ans == NULL)
  41             return NULL;
  42
  43         if (ans[0] == '?' || ans[0] == '\0') {
  44             puts("Options are:");
  45             print_sw(ALL, ansp, "", stdout);
  46             free(ans);
  47             continue;
  48         }
  49         add_history(ans);
  50         strncpy(ansbuf, ans, sizeof(ansbuf));
  51         ansbuf[sizeof(ansbuf) - 1] = '\0';
  52         free(ans);
  53
  54         cpp = brkstring(ansbuf, " ", NULL);
  55         switch (smatch(*cpp, ansp)) {
  56             case AMBIGSW:
  57                 ambigsw(*cpp, ansp);
  58                 continue;
  59             case UNKWNSW:
  60                 printf(" -%s unknown. Hit <CR> for help.\n", *cpp);
  61                 continue;
  62             default:
  63                 return cpp;
  64         }
  65     }
  66 }
  67
  68 static void
  69 initialize_readline(void)
  70 {
  71     rl_readline_name = "Nmh";
  72     rl_attempted_completion_function = nmh_completion;
  73 }
  74
  75 static char **
  76 nmh_completion(const char *text, int start, int end)
  77 {
  78     NMH_UNUSED (end);
  79
  80     if (start == 0)
  81         return rl_completion_matches(text, nmh_command_generator);
  82
  83     return NULL;
  84 }
  85
  86 static char *
  87 nmh_command_generator(const char *text, int state)
  88 {
  89     static int list_index, len;
  90     char *name, *p;
  91     char buf[256];
  92
  93     if (!state) {
  94         list_index = 0;
  95         len = strlen(text);
  96     }
  97
  98     while ((name = rl_cmds[list_index].sw)) {
  99         list_index++;
 100         strncpy(buf, name, sizeof(buf));
 101         buf[sizeof(buf) - 1] = '\0';
 102         p = *brkstring(buf, " ", NULL);
 103         if (strncmp(p, text, len) == 0)
 104             return strdup(p);
 105     }
 106
 107     return NULL;
 108 }
 109 #endif /* READLINE_SUPPORT */