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