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 #include <errno.h>
  15
  16 #ifdef READLINE_SUPPORT
  17 #include <readline/readline.h>
  18 #include <readline/history.h>
  19
  20 static struct swit *rl_cmds;
  21
  22 static char *nmh_command_generator(const char *, int);
  23 static char **nmh_completion(const char *, int, int);
  24 static void initialize_readline(void);
  25
  26 static char ansbuf[BUFSIZ];
  27
  28 /*
  29  * getans, but with readline support
  30  */
  31
  32 char **
  33 getans_via_readline(char *prompt, struct swit *ansp)
  34 {
  35     char *ans, **cpp;
  36
  37     initialize_readline();
  38     rl_cmds = ansp;
  39
  40     for (;;) {
  41         ans = readline(prompt);
  42         /*
  43          * If we get an EOF, return
  44          */
  45
  46         if (ans == NULL)
  47             return NULL;
  48
  49         if (ans[0] == '?' || ans[0] == '\0') {
  50             printf("Options are:\n");
  51             print_sw(ALL, ansp, "", stdout);
  52             free(ans);
  53             continue;
  54         }
  55         add_history(ans);
  56         strncpy(ansbuf, ans, sizeof(ansbuf));
  57         ansbuf[sizeof(ansbuf) - 1] = '\0';
  58         cpp = brkstring(ansbuf, " ", NULL);
  59         switch (smatch(*cpp, ansp)) {
  60             case AMBIGSW:
  61                 ambigsw(*cpp, ansp);
  62                 continue;
  63             case UNKWNSW:
  64                 printf(" -%s unknown. Hit <CR> for help.\n", *cpp);
  65                 continue;
  66             default:
  67                 free(ans);
  68                 return cpp;
  69         }
  70         free(ans);
  71     }
  72 }
  73
  74 static void
  75 initialize_readline(void)
  76 {
  77     rl_readline_name = "Nmh";
  78     rl_attempted_completion_function = nmh_completion;
  79 }
  80
  81 static char **
  82 nmh_completion(const char *text, int start, int end)
  83 {
  84     char **matches;
  85
  86     NMH_UNUSED (end);
  87
  88     matches = (char **) NULL;
  89
  90     if (start == 0)
  91         matches = rl_completion_matches(text, nmh_command_generator);
  92
  93     return matches;
  94 }
  95
  96 static char *
  97 nmh_command_generator(const char *text, int state)
  98 {
  99     static int list_index, len;
 100     char *name, *p;
 101     char buf[256];
 102
 103     if (!state) {
 104         list_index = 0;
 105         len = strlen(text);
 106     }
 107
 108     while ((name = rl_cmds[list_index].sw)) {
 109         list_index++;
 110         strncpy(buf, name, sizeof(buf));
 111         buf[sizeof(buf) - 1] = '\0';
 112         p = *brkstring(buf, " ", NULL);
 113         if (strncmp(p, text, len) == 0)
 114         return strdup(p);
 115     }
 116
 117     return NULL;
 118 }
 119 #endif /* READLINE_SUPPORT */
 120