Standard C has functions to do this, but they aren't very safe: null
characters and even (for @code{gets}) long lines can confuse them. So
-@theglibc{} provides the nonstandard @code{getline} function that
-makes it easy to read lines reliably.
+@theglibc{} provides the @code{getline} function that makes it easy to
+read lines reliably.
-Another GNU extension, @code{getdelim}, generalizes @code{getline}. It
-reads a delimited record, defined as everything through the next
-occurrence of a specified delimiter character.
+The @code{getdelim} function is a generalized version of @code{getline}.
+It reads a delimited record, defined as everything through the next
+occurrence of a specified delimiter character. These functions were
+both GNU extensions until standardized by POSIX.1-2008.
All these functions are declared in @file{stdio.h}.
-@deftypefun ssize_t getline (char **@var{lineptr}, size_t *@var{n}, FILE *@var{stream})
-@standards{GNU, stdio.h}
+@deftypefun ssize_t getline (char **restrict @var{lineptr}, size_t *restrict @var{n}, FILE *restrict @var{stream})
+@standards{POSIX.1-2008, stdio.h}
@safety{@prelim{}@mtsafe{}@asunsafe{@asucorrupt{} @ascuheap{}}@acunsafe{@aculock{} @acucorrupt{} @acsmem{}}}
@c Besides the usual possibility of getting an inconsistent stream in a
@c signal handler or leaving it inconsistent in case of cancellation,
This value enables you to distinguish null characters that are part of
the line from the null character inserted as a terminator.
-This function is a GNU extension, but it is the recommended way to read
-lines from a stream. The alternative standard functions are unreliable.
+This function was originally a GNU extension, but was added in
+POSIX.1-2008.
If an error occurs or end of file is reached without any bytes read,
@code{getline} returns @code{-1}.
@end deftypefun
-@deftypefun ssize_t getdelim (char **@var{lineptr}, size_t *@var{n}, int @var{delimiter}, FILE *@var{stream})
-@standards{GNU, stdio.h}
+@deftypefun ssize_t getdelim (char **restrict @var{lineptr}, size_t *restrict @var{n}, int @var{delimiter}, FILE *restrict @var{stream})
+@standards{POSIX.1-2008, stdio.h}
@safety{@prelim{}@mtsafe{}@asunsafe{@asucorrupt{} @ascuheap{}}@acunsafe{@aculock{} @acucorrupt{} @acsmem{}}}
@c See the getline @acucorrupt note.
This function is like @code{getline} except that the character which
and a terminating null. Like @code{getline}, @code{getdelim} makes
@var{lineptr} bigger if it isn't big enough.
+This function was originally a GNU extension, but was added in
+POSIX.1-2008.
+
@code{getline} is in fact implemented in terms of @code{getdelim}, just
like this: