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 libc_hidden_proto(fgets_unlocked)
  11
  12 #ifdef __DO_UNLOCKED
  13
  14 libc_hidden_proto(__fgetc_unlocked)
  15
  16 char *fgets_unlocked(char *__restrict s, int n,
  17                                            register FILE * __restrict stream)
  18 {
  19         register char *p;
  20         int c;
  21
  22         __STDIO_STREAM_VALIDATE(stream);
  23
  24 #ifdef __UCLIBC_MJN3_ONLY__
  25 #warning CONSIDER: What should fgets do if n <= 0?
  26 #endif /* __UCLIBC_MJN3_ONLY__ */
  27         /* Should we assert here?  Or set errno?  Or just fail... */
  28         if (n <= 0) {
  29 /*              __set_errno(EINVAL); */
  30                 goto ERROR;
  31         }
  32
  33         p = s;
  34
  35         while (--n) {
  36                 if (__STDIO_STREAM_CAN_USE_BUFFER_GET(stream)) {
  37                         if ((*p++ = __STDIO_STREAM_BUFFER_GET(stream)) == '\n') {
  38                                 break;
  39                         }
  40                 } else {
  41                         if ((c = __fgetc_unlocked(stream)) == EOF) {
  42                                 if (__FERROR_UNLOCKED(stream)) {
  43                                         goto ERROR;
  44                                 }
  45                                 break;
  46                         }
  47                         if ((*p++ = c) == '\n') {
  48                                 break;
  49                         }
  50                 }
  51         }
  52
  53 #ifdef __UCLIBC_MJN3_ONLY__
  54 #warning CONSIDER: If n==1 and not at EOF, should fgets return an empty string?
  55 #endif /* __UCLIBC_MJN3_ONLY__ */
  56         if (p > s) {
  57                 *p = 0;
  58                 return s;
  59         }
  60
  61  ERROR:
  62         return NULL;
  63 }
  64 libc_hidden_def(fgets_unlocked)
  65
  66 #ifndef __UCLIBC_HAS_THREADS__
  67 strong_alias(fgets_unlocked,fgets)
  68 libc_hidden_proto(fgets)
  69 libc_hidden_def(fgets)
  70 #endif
  71
  72 #elif defined __UCLIBC_HAS_THREADS__
  73
  74 char *fgets(char *__restrict s, int n,
  75                         register FILE * __restrict stream)
  76 {
  77         char *retval;
  78         __STDIO_AUTO_THREADLOCK_VAR;
  79
  80         __STDIO_AUTO_THREADLOCK(stream);
  81
  82         retval = fgets_unlocked(s, n, stream);
  83
  84         __STDIO_AUTO_THREADUNLOCK(stream);
  85
  86         return retval;
  87 }
  88 libc_hidden_proto(fgets)
  89 libc_hidden_def(fgets)
  90
  91 #endif