buf.c revision 1.8
1 /* buf.c: This file contains the scratch-file buffer rountines for the 2 ed line editor. */ 3 /*- 4 * Copyright (c) 1992 The Regents of the University of California. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * Rodney Ruddock of the University of Guelph. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 */ 38 39 #ifndef lint 40 /*static char sccsid[] = "from: @(#)buf.c 5.5 (Berkeley) 3/28/93";*/ 41 static char rcsid[] = "$Id: buf.c,v 1.8 1993/08/01 18:59:50 mycroft Exp $"; 42 #endif /* not lint */ 43 44 #include <stdio.h> 45 #include <stdlib.h> 46 #include <string.h> 47 #include <sys/file.h> 48 #include <unistd.h> 49 50 #include "ed.h" 51 52 extern char errmsg[]; 53 54 FILE *sfp; /* scratch file pointer */ 55 char *sfbuf = NULL; /* scratch file input buffer */ 56 int sfbufsz = 0; /* scratch file input buffer size */ 57 off_t sfseek; /* scratch file position */ 58 int seek_write; /* seek before writing */ 59 line_t line0; /* initial node of line queue */ 60 61 /* gettxt: get a line of text from the scratch file; return pointer 62 to the text */ 63 char * 64 gettxt(lp) 65 line_t *lp; 66 { 67 int len, ct; 68 69 if (lp == &line0) 70 return NULL; 71 seek_write = 1; /* force seek on write */ 72 /* out of position */ 73 if (sfseek != lp->seek) { 74 sfseek = lp->seek; 75 if (fseek(sfp, sfseek, SEEK_SET) < 0) { 76 fprintf(stderr, "%s\n", strerror(errno)); 77 sprintf(errmsg, "cannot seek temp file"); 78 return NULL; 79 } 80 } 81 len = lp->len & ~ACTV; 82 CKBUF(sfbuf, sfbufsz, len + 1, NULL); 83 if ((ct = fread(sfbuf, sizeof(char), len, sfp)) < 0 || ct != len) { 84 fprintf(stderr, "%s\n", strerror(errno)); 85 sprintf(errmsg, "cannot read temp file"); 86 return NULL; 87 } 88 sfseek += len; /* update file position */ 89 sfbuf[len] = '\0'; 90 return sfbuf; 91 } 92 93 94 extern long curln; 95 extern long lastln; 96 97 /* puttxt: write a line of text to the scratch file and add a line node 98 to the editor buffer; return a pointer to the end of the text */ 99 char * 100 puttxt(cs) 101 char *cs; 102 { 103 line_t *lp; 104 int len, ct; 105 char *s; 106 107 if ((lp = (line_t *) malloc(sizeof(line_t))) == NULL) { 108 fprintf(stderr, "%s\n", strerror(errno)); 109 sprintf(errmsg, "out of memory"); 110 return NULL; 111 } 112 /* assert: cs is '\n' terminated */ 113 for (s = cs; *s != '\n'; s++) 114 ; 115 if (s - cs >= LINECHARS) { 116 sprintf(errmsg, "line too long"); 117 return NULL; 118 } 119 len = (s - cs) & ~ACTV; 120 /* out of position */ 121 if (seek_write) { 122 if (fseek(sfp, 0L, SEEK_END) < 0) { 123 fprintf(stderr, "%s\n", strerror(errno)); 124 sprintf(errmsg, "cannot seek temp file"); 125 return NULL; 126 } 127 sfseek = ftell(sfp); 128 seek_write = 0; 129 } 130 /* assert: spl1() */ 131 if ((ct = fwrite(cs, sizeof(char), len, sfp)) < 0 || ct != len) { 132 sfseek = -1; 133 fprintf(stderr, "%s\n", strerror(errno)); 134 sprintf(errmsg, "cannot write temp file"); 135 return NULL; 136 } 137 lp->len = len; 138 lp->seek = sfseek; 139 lpqueue(lp); 140 sfseek += len; /* update file position */ 141 return ++s; 142 } 143 144 145 /* lpqueue: add a line node in the editor buffer after the current line */ 146 void 147 lpqueue(lp) 148 line_t *lp; 149 { 150 line_t *cp; 151 152 cp = getlp(curln); /* this getlp last! */ 153 insqueue(lp, cp); 154 lastln++; 155 curln++; 156 } 157 158 159 /* getaddr: return line number of pointer */ 160 long 161 getaddr(lp) 162 line_t *lp; 163 { 164 line_t *cp = &line0; 165 long n = 0; 166 167 while (cp != lp && (cp = cp->next) != &line0) 168 n++; 169 if (n && cp == &line0) { 170 sprintf(errmsg, "invalid address"); 171 return ERR; 172 } 173 return n; 174 } 175 176 177 /* getlp: return pointer to a line node in the editor buffer */ 178 line_t * 179 getlp(n) 180 long n; 181 { 182 static line_t *lp = &line0; 183 static long on = 0; 184 185 spl1(); 186 if (n > on) 187 if (n <= (on + lastln) >> 1) 188 for (; on < n; on++) 189 lp = lp->next; 190 else { 191 lp = line0.prev; 192 for (on = lastln; on > n; on--) 193 lp = lp->prev; 194 } 195 else 196 if (n >= on >> 1) 197 for (; on > n; on--) 198 lp = lp->prev; 199 else { 200 lp = &line0; 201 for (on = 0; on < n; on++) 202 lp = lp->next; 203 } 204 spl0(); 205 return lp; 206 } 207 208 209 char sfn[15] = ""; /* scratch file name */ 210 211 /* sbopen: open scratch file */ 212 sbopen() 213 { 214 strcpy(sfn, "/tmp/ed.XXXXXX"); 215 if (mktemp(sfn) == NULL || (sfp = fopen(sfn, "w+")) == NULL) { 216 fprintf(stderr, "%s: %s\n", sfn, strerror(errno)); 217 sprintf(errmsg, "cannot open temp file"); 218 return ERR; 219 } 220 return 0; 221 } 222 223 224 /* sbclose: close scratch file */ 225 sbclose() 226 { 227 if (sfp) { 228 if (fclose(sfp) < 0) { 229 fprintf(stderr, "%s: %s\n", sfn, strerror(errno)); 230 sprintf(errmsg, "cannot close temp file"); 231 return ERR; 232 } 233 sfp = NULL; 234 unlink(sfn); 235 } 236 sfseek = seek_write = 0; 237 return 0; 238 } 239 240 241 /* quit: remove scratch file and exit */ 242 void 243 quit(n) 244 int n; 245 { 246 if (sfp) { 247 fclose(sfp); 248 unlink(sfn); 249 } 250 exit(n); 251 } 252 253 254 unsigned char ctab[256]; /* character translation table */ 255 256 /* init_buf: open scratch buffer; initialize line queue */ 257 void 258 init_buf() 259 { 260 int i = 0; 261 262 if (sbopen() < 0) 263 quit(2); 264 requeue(&line0, &line0); 265 for (i = 0; i < 256; i++) 266 ctab[i] = i; 267 } 268 269 270 /* translit: translate characters in a string */ 271 char * 272 translit(s, len, from, to) 273 char *s; 274 int len; 275 int from; 276 int to; 277 { 278 static int i = 0; 279 280 unsigned char *us; 281 282 ctab[i] = i; /* restore table to initial state */ 283 ctab[i = from] = to; 284 for (us = (unsigned char *) s; len-- > 0; us++) 285 *us = ctab[*us]; 286 return s; 287 } 288 289 290
Indexes created Mon Oct 13 15:10:03 GMT 2025