libc/stdio/fgets.c

   1 /* Copyright (C) 2004       Manuel Novoa III    <mjn3@codepoet.org>
   2  *
   3  * GNU Library General Public License (LGPL) version 2 or later.
   4  *
   5  * Dedicated to Toni.  See uClibc/DEDICATION.mjn3 for details.
   6  */
   7
   8 #include "_stdio.h"
   9
  10
  11 #ifdef __DO_UNLOCKED
  12
  13
  14 char *fgets_unlocked(char *__restrict s, int n,
  15                                            register FILE * __restrict stream)
  16 {
  17         register char *p;
  18         int c;
  19
  20         __STDIO_STREAM_VALIDATE(stream);
  21
  22 #ifdef __UCLIBC_MJN3_ONLY__
  23 #warning CONSIDER: What should fgets do if n <= 0?
  24 #endif /* __UCLIBC_MJN3_ONLY__ */
  25         /* Should we assert here?  Or set errno?  Or just fail... */
  26         if (n <= 0) {
  27 /*              __set_errno(EINVAL); */
  28                 goto ERROR;
  29         }
  30
  31         p = s;
  32
  33         while (--n) {
  34                 if (__STDIO_STREAM_CAN_USE_BUFFER_GET(stream)) {
  35                         if ((*p++ = __STDIO_STREAM_BUFFER_GET(stream)) == '\n') {
  36                                 break;
  37                         }
  38                 } else {
  39                         if ((c = __fgetc_unlocked(stream)) == EOF) {
  40                                 if (__FERROR_UNLOCKED(stream)) {
  41                                         goto ERROR;
  42                                 }
  43                                 break;
  44                         }
  45                         if ((*p++ = c) == '\n') {
  46                                 break;
  47                         }
  48                 }
  49         }
  50
  51 #ifdef __UCLIBC_MJN3_ONLY__
  52 #warning CONSIDER: If n==1 and not at EOF, should fgets return an empty string?
  53 #endif /* __UCLIBC_MJN3_ONLY__ */
  54         if (p > s) {
  55                 *p = 0;
  56                 return s;
  57         }
  58
  59  ERROR:
  60         return NULL;
  61 }
  62 libc_hidden_def(fgets_unlocked)
  63
  64 #ifndef __UCLIBC_HAS_THREADS__
  65 strong_alias(fgets_unlocked,fgets)
  66 libc_hidden_def(fgets)
  67 #endif
  68
  69 #elif defined __UCLIBC_HAS_THREADS__
  70
  71 char *fgets(char *__restrict s, int n,
  72                         register FILE * __restrict stream)
  73 {
  74         char *retval;
  75         __STDIO_AUTO_THREADLOCK_VAR;
  76
  77         __STDIO_AUTO_THREADLOCK(stream);
  78
  79         retval = fgets_unlocked(s, n, stream);
  80
  81         __STDIO_AUTO_THREADUNLOCK(stream);
  82
  83         return retval;
  84 }
  85 libc_hidden_def(fgets)
  86
  87 #endif