1 /*- 2 * Copyright (c) 1992, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * Rodney Ruddock of the University of Guelph. 7 * 8 * %sccs.include.redist.c% 9 */ 10 11 #ifndef lint 12 static char sccsid[] = "@(#)get_line.c 8.1 (Berkeley) 05/31/93"; 13 #endif /* not lint */ 14 15 #include <sys/types.h> 16 17 #include <regex.h> 18 #include <setjmp.h> 19 #include <stdio.h> 20 #include <string.h> 21 22 #ifdef DBI 23 #include <db.h> 24 #endif 25 26 #include "ed.h" 27 #include "extern.h" 28 29 /* 30 * Get the specified line from the buffer. Note that in the buffer 31 * we stored lengths of text, not strings (NULL terminated, except 32 * under MEMORY). So we want to put a terminating NULL in for 33 * whatever command is going to be handling the line. 34 */ 35 36 /* these variables are here (instead of main and ed.h) because they 37 * are only used with the buffer when run under STDIO. STDIO is a 38 * resource pig with most of the OS's I've tested this with. The 39 * use of these variables improves performance up to 100% in several 40 * cases. The piggyness is thus: fseek causes the current STDIO buf 41 * to be flushed out and a new one read in...even when it is not necessary! 42 * Read 512 (or 1024) when you don't have to for almost every access 43 * and you'll slow down too. So these variable are used to control unneeded 44 * fseeks. 45 * I've been told the newer BSD STDIO has fixed this, but don't 46 * currently have a copy. 47 */ 48 int file_loc=0; 49 50 /* Get a particular line of length len from ed's buffer and place it in 51 * 'text', the standard repository for the "current" line. 52 */ 53 void 54 get_line(loc, len) 55 #ifdef STDIO 56 long loc; 57 #endif 58 #ifdef DBI 59 recno_t loc; 60 #endif 61 #ifdef MEMORY 62 char *loc; 63 #endif 64 int len; 65 { 66 #ifdef DBI 67 DBT db_key, db_data; 68 #endif 69 int l_jmp_flag; 70 71 if (l_jmp_flag = setjmp(ctrl_position2)) { 72 text[0] = '\0'; 73 return; 74 } 75 76 sigspecial2 = 1; 77 #ifdef STDIO 78 79 if (loc == 0L) { 80 text[0] = '\0'; 81 return; 82 } 83 if (file_loc != loc) 84 fseek(fhtmp, loc, 0); 85 file_seek = 1; 86 file_loc = loc + fread(text, sizeof(char), len, fhtmp); 87 #endif 88 89 #ifdef DBI 90 if (loc == (recno_t)0) { 91 text[0] = '\0'; 92 return; 93 } 94 (db_key.data) = &loc; 95 (db_key.size) = sizeof(recno_t); 96 (dbhtmp->get) (dbhtmp, &db_key, &db_data, (u_int) 0); 97 strcpy(text, db_data.data); 98 #endif 99 100 #ifdef MEMORY 101 if (loc == (char *)NULL) { 102 text[0] = '\0'; 103 return; 104 } 105 memmove(text, loc, len); 106 #endif 107 text[len] = '\0'; 108 sigspecial2 = 0; 109 } 110