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
  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 getans_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             printf("Options are:\n");
  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         cpp = brkstring(ansbuf, " ", NULL);
  57         switch (smatch(*cpp, ansp)) {
  58             case AMBIGSW:
  59                 ambigsw(*cpp, ansp);
  60                 continue;
  61             case UNKWNSW:
  62                 printf(" -%s unknown. Hit <CR> for help.\n", *cpp);
  63                 continue;
  64             default:
  65                 free(ans);
  66                 return cpp;
  67         }
  68         free(ans);
  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     char **matches;
  83
  84     NMH_UNUSED (end);
  85
  86     matches = (char **) NULL;
  87
  88     if (start == 0)
  89         matches = rl_completion_matches(text, nmh_command_generator);
  90
  91     return matches;
  92 }
  93
  94 static char *
  95 nmh_command_generator(const char *text, int state)
  96 {
  97     static int list_index, len;
  98     char *name, *p;
  99     char buf[256];
 100
 101     if (!state) {
 102         list_index = 0;
 103         len = strlen(text);
 104     }
 105
 106     while ((name = rl_cmds[list_index].sw)) {
 107         list_index++;
 108         strncpy(buf, name, sizeof(buf));
 109         buf[sizeof(buf) - 1] = '\0';
 110         p = *brkstring(buf, " ", NULL);
 111         if (strncmp(p, text, len) == 0)
 112         return strdup(p);
 113     }
 114
 115     return NULL;
 116 }
 117 #endif /* READLINE_SUPPORT */
 118