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 #include <setjmp.h>
  13 #include <signal.h>
  14
  15 #ifdef READLINE_SUPPORT
  16 #include <readline/readline.h>
  17 #include <readline/history.h>
  18
  19 static struct swit *rl_cmds;
  20
  21 static char *nmh_command_generator(const char *, int);
  22 static char **nmh_completion(const char *, int, int);
  23 static void initialize_readline(void);
  24
  25 static char ansbuf[BUFSIZ];
  26
  27 /*
  28  * getans, but with readline support
  29  */
  30
  31 char **
  32 getans_via_readline(char *prompt, struct swit *ansp)
  33 {
  34     char *ans, **cpp;
  35
  36     initialize_readline();
  37     rl_cmds = ansp;
  38
  39     for (;;) {
  40         ans = readline(prompt);
  41         /*
  42          * If we get an EOF, return
  43          */
  44
  45         if (ans == NULL)
  46             return NULL;
  47
  48         if (ans[0] == '?' || ans[0] == '\0') {
  49             printf("Options are:\n");
  50             print_sw(ALL, ansp, "", stdout);
  51             free(ans);
  52             continue;
  53         }
  54         add_history(ans);
  55         strncpy(ansbuf, ans, sizeof(ansbuf));
  56         ansbuf[sizeof(ansbuf) - 1] = '\0';
  57         cpp = brkstring(ansbuf, " ", NULL);
  58         switch (smatch(*cpp, ansp)) {
  59             case AMBIGSW:
  60                 ambigsw(*cpp, ansp);
  61                 continue;
  62             case UNKWNSW:
  63                 printf(" -%s unknown. Hit <CR> for help.\n", *cpp);
  64                 continue;
  65             default:
  66                 free(ans);
  67                 return cpp;
  68         }
  69         free(ans);
  70     }
  71 }
  72
  73 static void
  74 initialize_readline(void)
  75 {
  76     rl_readline_name = "Nmh";
  77     rl_attempted_completion_function = nmh_completion;
  78 }
  79
  80 static char **
  81 nmh_completion(const char *text, int start, int end)
  82 {
  83     char **matches;
  84
  85     NMH_UNUSED (end);
  86
  87     matches = (char **) NULL;
  88
  89     if (start == 0)
  90         matches = rl_completion_matches(text, nmh_command_generator);
  91
  92     return matches;
  93 }
  94
  95 static char *
  96 nmh_command_generator(const char *text, int state)
  97 {
  98     static int list_index, len;
  99     char *name, *p;
 100     char buf[256];
 101
 102     if (!state) {
 103         list_index = 0;
 104         len = strlen(text);
 105     }
 106
 107     while ((name = rl_cmds[list_index].sw)) {
 108         list_index++;
 109         strncpy(buf, name, sizeof(buf));
 110         buf[sizeof(buf) - 1] = '\0';
 111         p = *brkstring(buf, " ", NULL);
 112         if (strncmp(p, text, len) == 0)
 113         return strdup(p);
 114     }
 115
 116     return NULL;
 117 }
 118 #endif /* READLINE_SUPPORT */
 119