| Mike Frysinger | 0184f1e | 2010-01-08 02:48:03 -0500 | [diff] [blame] | 1 | /* getline.c -- Replacement for GNU C library function getline |
| 2 | |
| 3 | Copyright (C) 1993, 1996, 2001, 2002 Free Software Foundation, Inc. |
| 4 | |
| 5 | This program is free software; you can redistribute it and/or |
| 6 | modify it under the terms of the GNU General Public License as |
| 7 | published by the Free Software Foundation; either version 2 of the |
| 8 | License, or (at your option) any later version. |
| 9 | |
| 10 | This program is distributed in the hope that it will be useful, but |
| 11 | WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 13 | General Public License for more details. |
| 14 | |
| 15 | You should have received a copy of the GNU General Public License |
| 16 | along with this program; if not, write to the Free Software |
| 17 | Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ |
| 18 | |
| 19 | /* Written by Jan Brittenson, bson@gnu.ai.mit.edu. */ |
| 20 | |
| 21 | #include <assert.h> |
| 22 | #include <stdio.h> |
| 23 | |
| 24 | /* Always add at least this many bytes when extending the buffer. */ |
| 25 | #define MIN_CHUNK 64 |
| 26 | |
| 27 | /* Read up to (and including) a TERMINATOR from STREAM into *LINEPTR |
| 28 | + OFFSET (and null-terminate it). *LINEPTR is a pointer returned from |
| 29 | malloc (or NULL), pointing to *N characters of space. It is realloc'd |
| 30 | as necessary. Return the number of characters read (not including the |
| 31 | null terminator), or -1 on error or EOF. |
| 32 | NOTE: There is another getstr() function declared in <curses.h>. */ |
| 33 | static int getstr(char **lineptr, size_t *n, FILE *stream, |
| 34 | char terminator, size_t offset) |
| 35 | { |
| 36 | int nchars_avail; /* Allocated but unused chars in *LINEPTR. */ |
| 37 | char *read_pos; /* Where we're reading into *LINEPTR. */ |
| 38 | int ret; |
| 39 | |
| 40 | if (!lineptr || !n || !stream) |
| 41 | return -1; |
| 42 | |
| 43 | if (!*lineptr) { |
| 44 | *n = MIN_CHUNK; |
| 45 | *lineptr = malloc(*n); |
| 46 | if (!*lineptr) |
| 47 | return -1; |
| 48 | } |
| 49 | |
| 50 | nchars_avail = *n - offset; |
| 51 | read_pos = *lineptr + offset; |
| 52 | |
| 53 | for (;;) { |
| 54 | register int c = getc(stream); |
| 55 | |
| 56 | /* We always want at least one char left in the buffer, since we |
| 57 | always (unless we get an error while reading the first char) |
| 58 | NUL-terminate the line buffer. */ |
| 59 | |
| 60 | assert(*n - nchars_avail == read_pos - *lineptr); |
| 61 | if (nchars_avail < 2) { |
| 62 | if (*n > MIN_CHUNK) |
| 63 | *n *= 2; |
| 64 | else |
| 65 | *n += MIN_CHUNK; |
| 66 | |
| 67 | nchars_avail = *n + *lineptr - read_pos; |
| 68 | *lineptr = realloc(*lineptr, *n); |
| 69 | if (!*lineptr) |
| 70 | return -1; |
| 71 | read_pos = *n - nchars_avail + *lineptr; |
| 72 | assert(*n - nchars_avail == read_pos - *lineptr); |
| 73 | } |
| 74 | |
| 75 | if (c == EOF || ferror (stream)) { |
| 76 | /* Return partial line, if any. */ |
| 77 | if (read_pos == *lineptr) |
| 78 | return -1; |
| 79 | else |
| 80 | break; |
| 81 | } |
| 82 | |
| 83 | *read_pos++ = c; |
| 84 | nchars_avail--; |
| 85 | |
| 86 | if (c == terminator) |
| 87 | /* Return the line. */ |
| 88 | break; |
| 89 | } |
| 90 | |
| 91 | /* Done - NUL terminate and return the number of chars read. */ |
| 92 | *read_pos = '\0'; |
| 93 | |
| 94 | ret = read_pos - (*lineptr + offset); |
| 95 | return ret; |
| 96 | } |
| 97 | |
| 98 | int getline (char **lineptr, size_t *n, FILE *stream) |
| 99 | { |
| 100 | return getstr(lineptr, n, stream, '\n', 0); |
| 101 | } |