1234852Sbapt/* getline.c -- Replacement for GNU C library function getline 2234852Sbapt 3234852SbaptCopyright (C) 1993, 1996, 2001-2002 Free Software Foundation, Inc. 4234852Sbapt 5234852SbaptThis program is free software; you can redistribute it and/or 6234852Sbaptmodify it under the terms of the GNU General Public License as 7234852Sbaptpublished by the Free Software Foundation; either version 2 of the 8234852SbaptLicense, or (at your option) any later version. 9234852Sbapt 10234852SbaptThis program is distributed in the hope that it will be useful, but 11234852SbaptWITHOUT ANY WARRANTY; without even the implied warranty of 12234852SbaptMERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 13General Public License for more details. 14 15You should have received a copy of the GNU General Public License 16along with this program; if not, write to the Free Software 17Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, 18USA. */ 19 20/* Written by Jan Brittenson, bson@gnu.ai.mit.edu. */ 21 22/* Specification. */ 23#include "getline.h" 24 25#include <stddef.h> 26#include <stdio.h> 27#include <string.h> 28#include <assert.h> 29 30/* Always add at least this many bytes when extending the buffer. */ 31#define MIN_CHUNK 64 32 33/* Reads up to (and including) a TERMINATOR from STREAM into *LINEPTR + OFFSET 34 (and null-terminate it). *LINEPTR is a pointer returned from new [] (or 35 NULL), pointing to *N characters of space. It is realloc'd as 36 necessary. Returns the number of characters read (not including the 37 null terminator), or -1 on error or immediate EOF. 38 NOTE: There is another getstr() function declared in <curses.h>. */ 39 40static int 41getstr (char **lineptr, size_t *n, FILE *stream, char terminator, size_t offset) 42{ 43 size_t nchars_avail; /* Allocated but unused chars in *LINEPTR. */ 44 char *read_pos; /* Where we're reading into *LINEPTR. */ 45 46 if (!lineptr || !n || !stream) 47 return -1; 48 49 if (!*lineptr) 50 { 51 *n = MIN_CHUNK; 52 *lineptr = new char[*n]; 53 } 54 55 nchars_avail = *n - offset; 56 read_pos = *lineptr + offset; 57 58 for (;;) 59 { 60 int c = getc (stream); 61 62 /* We always want at least one char left in the buffer, since we 63 always (unless we get an error while reading the first char) 64 NUL-terminate the line buffer. */ 65 66 assert (*n - nchars_avail == (size_t) (read_pos - *lineptr)); 67 if (nchars_avail < 2) 68 { 69 if (*n > MIN_CHUNK) 70 *n *= 2; 71 else 72 *n += MIN_CHUNK; 73 74 nchars_avail = *n + *lineptr - read_pos; 75 char *new_line = new char[*n]; 76 if (*lineptr) 77 { 78 memcpy (new_line, *lineptr, read_pos - *lineptr); 79 delete[] *lineptr; 80 } 81 *lineptr = new_line; 82 read_pos = *n - nchars_avail + *lineptr; 83 assert (*n - nchars_avail == (size_t) (read_pos - *lineptr)); 84 } 85 86 if (c == EOF || ferror (stream)) 87 { 88 /* Return partial line, if any. */ 89 if (read_pos == *lineptr) 90 return -1; 91 else 92 break; 93 } 94 95 *read_pos++ = c; 96 nchars_avail--; 97 98 if (c == terminator) 99 /* Return the line. */ 100 break; 101 } 102 103 /* Done - NUL terminate and return the number of chars read. */ 104 *read_pos = '\0'; 105 106 return read_pos - (*lineptr + offset); 107} 108 109int 110get_line (char **lineptr, size_t *n, FILE *stream) 111{ 112 return getstr (lineptr, n, stream, '\n', 0); 113} 114 115int 116get_delim (char **lineptr, size_t *n, int delimiter, FILE *stream) 117{ 118 return getstr (lineptr, n, stream, delimiter, 0); 119} 120