1 /* $NetBSD: pager.c,v 1.2 2009/07/20 04:59:03 kiyohara Exp $ */ 2 3 /*- 4 * Copyright (c) 1998 Michael Smith <msmith@freebsd.org> 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 /* 29 * Simple paged-output and paged-viewing functions 30 */ 31 32 #include <sys/cdefs.h> 33 34 #include "lib/libsa/stand.h" 35 #include "lib/libsa/loadfile.h" 36 37 #include <bootstrap.h> 38 39 static int p_maxlines = -1; 40 static int p_freelines; 41 42 static char *pager_prompt1 = " --more-- <space> page down <enter> line down <q> quit "; 43 static char *pager_blank = " "; 44 45 /* 46 * 'open' the pager 47 */ 48 void 49 pager_open(void) 50 { 51 int nlines; 52 char *cp, *lp; 53 54 nlines = 24; /* sensible default */ 55 if ((cp = getenv("LINES")) != NULL) { 56 nlines = strtol(cp, &lp, 0); 57 } 58 59 p_maxlines = nlines - 1; 60 if (p_maxlines < 1) 61 p_maxlines = 1; 62 p_freelines = p_maxlines; 63 } 64 65 /* 66 * 'close' the pager 67 */ 68 void 69 pager_close(void) 70 { 71 p_maxlines = -1; 72 } 73 74 /* 75 * Emit lines to the pager; may not return until the user 76 * has responded to the prompt. 77 * 78 * Will return nonzero if the user enters 'q' or 'Q' at the prompt. 79 * 80 * XXX note that this watches outgoing newlines (and eats them), but 81 * does not handle wrap detection (req. count of columns). 82 */ 83 84 int 85 pager_output(const char *cp) 86 { 87 int action; 88 89 if (cp == NULL) 90 return(0); 91 92 for (;;) { 93 if (*cp == 0) 94 return(0); 95 96 putchar(*cp); /* always emit character */ 97 98 if (*(cp++) == '\n') { /* got a newline? */ 99 p_freelines--; 100 if (p_freelines <= 0) { 101 printf("%s", pager_prompt1); 102 action = 0; 103 while (action == 0) { 104 switch(getchar()) { 105 case '\r': 106 case '\n': 107 p_freelines = 1; 108 action = 1; 109 break; 110 case ' ': 111 p_freelines = p_maxlines; 112 action = 1; 113 break; 114 case 'q': 115 case 'Q': 116 action = 2; 117 break; 118 default: 119 break; 120 } 121 } 122 printf("\r%s\r", pager_blank); 123 if (action == 2) 124 return(1); 125 } 126 } 127 } 128 } 129 130 /* 131 * Display from (fd). 132 */ 133 int 134 pager_file(const char *fname) 135 { 136 char buf[80]; 137 size_t hmuch; 138 int fd; 139 int result; 140 141 if ((fd = open(fname, O_RDONLY)) == -1) { 142 printf("can't open '%s': %s\n", fname, strerror(errno)); 143 return(-1); 144 } 145 146 for (;;) { 147 hmuch = read(fd, buf, sizeof(buf) - 1); 148 if (hmuch == -1) { 149 result = -1; 150 break; 151 } 152 if (hmuch == 0) { 153 result = 0; 154 break; 155 } 156 buf[hmuch] = 0; 157 if (pager_output(buf)) { 158 result = 1; 159 break; 160 } 161 } 162 close(fd); 163 return(result); 164 } 165