| lh | 9ed821d | 2023-04-07 01:36:19 -0700 | [diff] [blame^] | 1 | |
| 2 | /* Copyright 1998 by the Massachusetts Institute of Technology. |
| 3 | * |
| 4 | * Permission to use, copy, modify, and distribute this |
| 5 | * software and its documentation for any purpose and without |
| 6 | * fee is hereby granted, provided that the above copyright |
| 7 | * notice appear in all copies and that both that copyright |
| 8 | * notice and this permission notice appear in supporting |
| 9 | * documentation, and that the name of M.I.T. not be used in |
| 10 | * advertising or publicity pertaining to distribution of the |
| 11 | * software without specific, written prior permission. |
| 12 | * M.I.T. makes no representations about the suitability of |
| 13 | * this software for any purpose. It is provided "as is" |
| 14 | * without express or implied warranty. |
| 15 | */ |
| 16 | |
| 17 | #include "ares_setup.h" |
| 18 | |
| 19 | #include "ares.h" |
| 20 | #include "ares_nowarn.h" |
| 21 | #include "ares_private.h" |
| 22 | |
| 23 | /* This is an internal function. Its contract is to read a line from |
| 24 | * a file into a dynamically allocated buffer, zeroing the trailing |
| 25 | * newline if there is one. The calling routine may call |
| 26 | * ares__read_line multiple times with the same buf and bufsize |
| 27 | * pointers; *buf will be reallocated and *bufsize adjusted as |
| 28 | * appropriate. The initial value of *buf should be NULL. After the |
| 29 | * calling routine is done reading lines, it should free *buf. |
| 30 | */ |
| 31 | int ares__read_line(FILE *fp, char **buf, size_t *bufsize) |
| 32 | { |
| 33 | char *newbuf; |
| 34 | size_t offset = 0; |
| 35 | size_t len; |
| 36 | |
| 37 | if (*buf == NULL) |
| 38 | { |
| 39 | *buf = ares_malloc(128); |
| 40 | if (!*buf) |
| 41 | return ARES_ENOMEM; |
| 42 | *bufsize = 128; |
| 43 | } |
| 44 | |
| 45 | for (;;) |
| 46 | { |
| 47 | int bytestoread = aresx_uztosi(*bufsize - offset); |
| 48 | |
| 49 | if (!fgets(*buf + offset, bytestoread, fp)) |
| 50 | return (offset != 0) ? 0 : (ferror(fp)) ? ARES_EFILE : ARES_EOF; |
| 51 | len = offset + strlen(*buf + offset); |
| 52 | if ((*buf)[len - 1] == '\n') |
| 53 | { |
| 54 | (*buf)[len - 1] = 0; |
| 55 | break; |
| 56 | } |
| 57 | offset = len; |
| 58 | if(len < *bufsize - 1) |
| 59 | continue; |
| 60 | |
| 61 | /* Allocate more space. */ |
| 62 | newbuf = ares_realloc(*buf, *bufsize * 2); |
| 63 | if (!newbuf) |
| 64 | { |
| 65 | ares_free(*buf); |
| 66 | *buf = NULL; |
| 67 | return ARES_ENOMEM; |
| 68 | } |
| 69 | *buf = newbuf; |
| 70 | *bufsize *= 2; |
| 71 | } |
| 72 | return ARES_SUCCESS; |
| 73 | } |