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

   1
   2 /*
   3  * getansreadline.c -- get an answer from the user, with readline
   4  *
   5  * This code is Copyright (c) 2012, by the authors of nmh.  See the
   6  * COPYRIGHT file in the root directory of the nmh distribution for
   7  * complete copyright information.
   8  */
   9
  10 #include <h/mh.h>
  11 #include <h/signals.h>
  12
  13 #ifdef READLINE_SUPPORT
  14 #include <readline/readline.h>
  15 #include <readline/history.h>
  16
  17 static struct swit *rl_cmds;
  18
  19 static char *nmh_command_generator(const char *, int);
  20 static char **nmh_completion(const char *, int, int);
  21 static void initialize_readline(void);
  22
  23 static char ansbuf[BUFSIZ];
  24
  25 /*
  26  * getans, but with readline support
  27  */
  28
  29 char **
  30 getans_via_readline(char *prompt, struct swit *ansp)
  31 {
  32     char *ans, **cpp;
  33
  34     initialize_readline();
  35     rl_cmds = ansp;
  36
  37     for (;;) {
  38         ans = readline(prompt);
  39         /*
  40          * If we get an EOF, return
  41          */
  42
  43         if (ans == NULL)
  44             return NULL;
  45
  46         if (ans[0] == '?' || ans[0] == '\0') {
  47             printf("Options are:\n");
  48             print_sw(ALL, ansp, "", stdout);
  49             free(ans);
  50             continue;
  51         }
  52         add_history(ans);
  53         strncpy(ansbuf, ans, sizeof(ansbuf));
  54         ansbuf[sizeof(ansbuf) - 1] = '\0';
  55         cpp = brkstring(ansbuf, " ", NULL);
  56         switch (smatch(*cpp, ansp)) {
  57             case AMBIGSW:
  58                 ambigsw(*cpp, ansp);
  59                 continue;
  60             case UNKWNSW:
  61                 printf(" -%s unknown. Hit <CR> for help.\n", *cpp);
  62                 continue;
  63             default:
  64                 free(ans);
  65                 return cpp;
  66         }
  67         free(ans);
  68     }
  69 }
  70
  71 static void
  72 initialize_readline(void)
  73 {
  74     rl_readline_name = "Nmh";
  75     rl_attempted_completion_function = nmh_completion;
  76 }
  77
  78 static char **
  79 nmh_completion(const char *text, int start, int end)
  80 {
  81     char **matches;
  82
  83     NMH_UNUSED (end);
  84
  85     matches = (char **) NULL;
  86
  87     if (start == 0)
  88         matches = rl_completion_matches(text, nmh_command_generator);
  89
  90     return matches;
  91 }
  92
  93 static char *
  94 nmh_command_generator(const char *text, int state)
  95 {
  96     static int list_index, len;
  97     char *name, *p;
  98     char buf[256];
  99
 100     if (!state) {
 101         list_index = 0;
 102         len = strlen(text);
 103     }
 104
 105     while ((name = rl_cmds[list_index].sw)) {
 106         list_index++;
 107         strncpy(buf, name, sizeof(buf));
 108         buf[sizeof(buf) - 1] = '\0';
 109         p = *brkstring(buf, " ", NULL);
 110         if (strncmp(p, text, len) == 0)
 111         return strdup(p);
 112     }
 113
 114     return NULL;
 115 }
 116 #endif /* READLINE_SUPPORT */
 117