1 /* callback.c -- functions to use readline as an X `callback' mechanism. */ 2 3 /* Copyright (C) 1987, 1989, 1992 Free Software Foundation, Inc. 4 5 This file is part of the GNU Readline Library, a library for 6 reading lines of text with interactive input and history editing. 7 8 The GNU Readline Library is free software; you can redistribute it 9 and/or modify it under the terms of the GNU General Public License 10 as published by the Free Software Foundation; either version 2, or 11 (at your option) any later version. 12 13 The GNU Readline Library is distributed in the hope that it will be 14 useful, but WITHOUT ANY WARRANTY; without even the implied warranty 15 of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 GNU General Public License for more details. 17 18 The GNU General Public License is often shipped with GNU software, and 19 is generally kept in a file called COPYING or LICENSE. If you do not 20 have a copy of the license, write to the Free Software Foundation, 21 59 Temple Place, Suite 330, Boston, MA 02111 USA. */ 22 #define READLINE_LIBRARY 23 24 #if defined (HAVE_CONFIG_H) 25 # include <config.h> 26 #endif 27 28 #include "rlconf.h" 29 30 #if defined (READLINE_CALLBACKS) 31 32 #include <sys/types.h> 33 34 #ifdef HAVE_STDLIB_H 35 # include <stdlib.h> 36 #else 37 # include "ansi_stdlib.h" 38 #endif 39 40 #include <stdio.h> 41 42 /* System-specific feature definitions and include files. */ 43 #include "rldefs.h" 44 #include "readline.h" 45 #include "rlprivate.h" 46 47 /* **************************************************************** */ 48 /* */ 49 /* Callback Readline Functions */ 50 /* */ 51 /* **************************************************************** */ 52 53 /* Allow using readline in situations where a program may have multiple 54 things to handle at once, and dispatches them via select(). Call 55 rl_callback_handler_install() with the prompt and a function to call 56 whenever a complete line of input is ready. The user must then 57 call rl_callback_read_char() every time some input is available, and 58 rl_callback_read_char() will call the user's function with the complete 59 text read in at each end of line. The terminal is kept prepped and 60 signals handled all the time, except during calls to the user's function. */ 61 62 rl_vcpfunc_t *rl_linefunc; /* user callback function */ 63 static int in_handler; /* terminal_prepped and signals set? */ 64 65 /* Make sure the terminal is set up, initialize readline, and prompt. */ 66 static void 67 _rl_callback_newline () 68 { 69 rl_initialize (); 70 71 if (in_handler == 0) 72 { 73 in_handler = 1; 74 75 (*rl_prep_term_function) (_rl_meta_flag); 76 77 #if defined (HANDLE_SIGNALS) 78 rl_set_signals (); 79 #endif 80 } 81 82 readline_internal_setup (); 83 } 84 85 /* Install a readline handler, set up the terminal, and issue the prompt. */ 86 void 87 rl_callback_handler_install (prompt, linefunc) 88 const char *prompt; 89 rl_vcpfunc_t *linefunc; 90 { 91 rl_set_prompt (prompt); 92 rl_linefunc = linefunc; 93 _rl_callback_newline (); 94 } 95 96 /* Read one character, and dispatch to the handler if it ends the line. */ 97 void 98 rl_callback_read_char () 99 { 100 char *line; 101 int eof; 102 103 if (rl_linefunc == NULL) 104 { 105 fprintf (stderr, "readline: readline_callback_read_char() called with no handler!\r\n"); 106 abort (); 107 } 108 109 eof = readline_internal_char (); 110 111 /* We loop in case some function has pushed input back with rl_execute_next. */ 112 for (;;) 113 { 114 if (rl_done) 115 { 116 line = readline_internal_teardown (eof); 117 118 (*rl_deprep_term_function) (); 119 #if defined (HANDLE_SIGNALS) 120 rl_clear_signals (); 121 #endif 122 in_handler = 0; 123 (*rl_linefunc) (line); 124 125 /* If the user did not clear out the line, do it for him. */ 126 if (rl_line_buffer[0]) 127 _rl_init_line_state (); 128 129 /* Redisplay the prompt if readline_handler_{install,remove} 130 not called. */ 131 if (in_handler == 0 && rl_linefunc) 132 _rl_callback_newline (); 133 } 134 if (rl_pending_input || _rl_pushed_input_available ()) 135 eof = readline_internal_char (); 136 else 137 break; 138 } 139 } 140 141 /* Remove the handler, and make sure the terminal is in its normal state. */ 142 void 143 rl_callback_handler_remove () 144 { 145 rl_linefunc = NULL; 146 if (in_handler) 147 { 148 in_handler = 0; 149 (*rl_deprep_term_function) (); 150 #if defined (HANDLE_SIGNALS) 151 rl_clear_signals (); 152 #endif 153 } 154 } 155 156 #endif 157