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
  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 getans_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             printf("Options are:\n");
  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         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                 free(ans);
  64                 return cpp;
  65         }
  66         free(ans);
  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     char **matches;
  81
  82     NMH_UNUSED (end);
  83
  84     matches = (char **) NULL;
  85
  86     if (start == 0)
  87         matches = rl_completion_matches(text, nmh_command_generator);
  88
  89     return matches;
  90 }
  91
  92 static char *
  93 nmh_command_generator(const char *text, int state)
  94 {
  95     static int list_index, len;
  96     char *name, *p;
  97     char buf[256];
  98
  99     if (!state) {
 100         list_index = 0;
 101         len = strlen(text);
 102     }
 103
 104     while ((name = rl_cmds[list_index].sw)) {
 105         list_index++;
 106         strncpy(buf, name, sizeof(buf));
 107         buf[sizeof(buf) - 1] = '\0';
 108         p = *brkstring(buf, " ", NULL);
 109         if (strncmp(p, text, len) == 0)
 110         return strdup(p);
 111     }
 112
 113     return NULL;
 114 }
 115 #endif /* READLINE_SUPPORT */
 116