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