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 #include "ambigsw.h"
  10 #include "print_sw.h"
  11
  12 #ifdef READLINE_SUPPORT
  13 #include <readline/readline.h>
  14 #include <readline/history.h>
  15
  16 static struct swit *rl_cmds;
  17
  18 static char *nmh_command_generator(const char *, int);
  19 static char **nmh_completion(const char *, int, int);
  20 static void initialize_readline(void);
  21
  22 static char ansbuf[BUFSIZ];
  23
  24 /*
  25  * getans, but with readline support
  26  */
  27
  28 char **
  29 read_switch_multiword_via_readline(char *prompt, struct swit *ansp)
  30 {
  31     char *ans, **cpp;
  32
  33     initialize_readline();
  34     rl_cmds = ansp;
  35
  36     for (;;) {
  37         ans = readline(prompt);
  38         /*
  39          * If we get an EOF, return
  40          */
  41
  42         if (ans == NULL)
  43             return NULL;
  44
  45         if (ans[0] == '?' || ans[0] == '\0') {
  46             puts("Options are:");
  47             print_sw(ALL, ansp, "", stdout);
  48             free(ans);
  49             continue;
  50         }
  51         add_history(ans);
  52         strncpy(ansbuf, ans, sizeof(ansbuf));
  53         ansbuf[sizeof(ansbuf) - 1] = '\0';
  54         free(ans);
  55
  56         cpp = brkstring(ansbuf, " ", NULL);
  57         switch (smatch(*cpp, ansp)) {
  58             case AMBIGSW:
  59                 ambigsw(*cpp, ansp);
  60                 continue;
  61             case UNKWNSW:
  62                 printf(" -%s unknown. Hit <CR> for help.\n", *cpp);
  63                 continue;
  64             default:
  65                 return cpp;
  66         }
  67     }
  68 }
  69
  70 static void
  71 initialize_readline(void)
  72 {
  73     rl_readline_name = "Nmh";
  74     rl_attempted_completion_function = nmh_completion;
  75 }
  76
  77 static char **
  78 nmh_completion(const char *text, int start, int end)
  79 {
  80     NMH_UNUSED (end);
  81
  82     if (start == 0)
  83         return rl_completion_matches(text, nmh_command_generator);
  84
  85     return NULL;
  86 }
  87
  88 static char *
  89 nmh_command_generator(const char *text, int state)
  90 {
  91     static int list_index, len;
  92     char *name, *p;
  93     char buf[256];
  94
  95     if (!state) {
  96         list_index = 0;
  97         len = strlen(text);
  98     }
  99
 100     while ((name = rl_cmds[list_index].sw)) {
 101         list_index++;
 102         strncpy(buf, name, sizeof(buf));
 103         buf[sizeof(buf) - 1] = '\0';
 104         p = *brkstring(buf, " ", NULL);
 105         if (strncmp(p, text, len) == 0)
 106             return strdup(p);
 107     }
 108
 109     return NULL;
 110 }
 111 #endif /* READLINE_SUPPORT */