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 "read_switch_multiword_via_readline.h"
  10 #include "smatch.h"
  11 #include "brkstring.h"
  12 #include "ambigsw.h"
  13 #include "print_sw.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 read_switch_multiword_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             puts("Options are:");
  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         free(ans);
  58
  59         cpp = brkstring(ansbuf, " ", NULL);
  60         switch (smatch(*cpp, ansp)) {
  61             case AMBIGSW:
  62                 ambigsw(*cpp, ansp);
  63                 continue;
  64             case UNKWNSW:
  65                 printf(" -%s unknown. Hit <CR> for help.\n", *cpp);
  66                 continue;
  67             default:
  68                 return cpp;
  69         }
  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     NMH_UNUSED (end);
  84
  85     if (start == 0)
  86         return rl_completion_matches(text, nmh_command_generator);
  87
  88     return NULL;
  89 }
  90
  91 static char *
  92 nmh_command_generator(const char *text, int state)
  93 {
  94     static int list_index, len;
  95     char *name, *p;
  96     char buf[256];
  97
  98     if (!state) {
  99         list_index = 0;
 100         len = strlen(text);
 101     }
 102
 103     while ((name = rl_cmds[list_index].sw)) {
 104         list_index++;
 105         strncpy(buf, name, sizeof(buf));
 106         buf[sizeof(buf) - 1] = '\0';
 107         p = *brkstring(buf, " ", NULL);
 108         if (strncmp(p, text, len) == 0)
 109             return strdup(p);
 110     }
 111
 112     return NULL;
 113 }
 114 #endif /* READLINE_SUPPORT */