diff options
Diffstat (limited to 'manual')
| -rw-r--r-- | manual/arith.texi | 12 | ||||
| -rw-r--r-- | manual/stdio.texi | 26 | ||||
| -rw-r--r-- | manual/time.texi | 3 | ||||
| -rw-r--r-- | manual/tunables.texi | 10 |
4 files changed, 34 insertions, 17 deletions
diff --git a/manual/arith.texi b/manual/arith.texi index 034d9d2..d500dcf 100644 --- a/manual/arith.texi +++ b/manual/arith.texi @@ -1233,25 +1233,33 @@ whose imaginary part is @var{y}, the absolute value is @w{@code{sqrt @pindex math.h @pindex stdlib.h -Prototypes for @code{abs}, @code{labs} and @code{llabs} are in @file{stdlib.h}; -@code{imaxabs} is declared in @file{inttypes.h}; +Prototypes for @code{abs}, @code{labs}, @code{llabs}, +@code{uabs}, @code{ulabs} and @code{ullabs} are in @file{stdlib.h}; +@code{imaxabs} and @code{uimaxabs} are declared in @file{inttypes.h}; the @code{fabs} functions are declared in @file{math.h}; the @code{cabs} functions are declared in @file{complex.h}. @deftypefun int abs (int @var{number}) @deftypefunx {long int} labs (long int @var{number}) @deftypefunx {long long int} llabs (long long int @var{number}) +@deftypefunx {unsigned int} uabs (int @var{number}) +@deftypefunx {unsigned long int} ulabs (long int @var{number}) +@deftypefunx {unsigned long long int} ullabs (long long int @var{number}) @deftypefunx intmax_t imaxabs (intmax_t @var{number}) +@deftypefunx uintmax_t uimaxabs (intmax_t @var{number}) @standards{ISO, stdlib.h} @standardsx{imaxabs, ISO, inttypes.h} +@standardsx{uimaxabs, ISO, inttypes.h} @safety{@prelim{}@mtsafe{}@assafe{}@acsafe{}} These functions return the absolute value of @var{number}. Most computers use a two's complement integer representation, in which the absolute value of @code{INT_MIN} (the smallest possible @code{int}) cannot be represented; thus, @w{@code{abs (INT_MIN)}} is not defined. +Using @code{uabs} avoids this. @code{llabs} and @code{imaxdiv} are new to @w{ISO C99}. +@code{uabs}, @code{ulabs}, @code{ullabs} and @code{uimaxabs} are new to @w{ISO C2Y}. See @ref{Integers} for a description of the @code{intmax_t} type. diff --git a/manual/stdio.texi b/manual/stdio.texi index 01b9f47..29ed720 100644 --- a/manual/stdio.texi +++ b/manual/stdio.texi @@ -1231,17 +1231,18 @@ convenient to have functions to read a line of text from a stream. 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, @@ -1274,15 +1275,15 @@ read (including the newline, but not including the terminating null). 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 @@ -1294,6 +1295,9 @@ The text is stored in @var{lineptr}, including the delimiter character 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: diff --git a/manual/time.texi b/manual/time.texi index 04c97f5..6b89b85 100644 --- a/manual/time.texi +++ b/manual/time.texi @@ -148,7 +148,8 @@ and pass them to the functions that convert them to broken-down time On POSIX-conformant systems, @code{time_t} is an integer type and its values represent the number of seconds elapsed since the @dfn{POSIX Epoch}, which is January 1, 1970, at 00:00:00 Coordinated Universal Time (UTC)@. -The count of seconds ignores leap seconds. +The count of seconds ignores leap seconds. Additionally, POSIX.1-2024 +added the requirement that @code{time_t} be at least 64 bits wide. @Theglibc{} additionally guarantees that @code{time_t} is a signed type, and that all of its functions operate correctly on negative diff --git a/manual/tunables.texi b/manual/tunables.texi index 7f0246c..d11ca7e 100644 --- a/manual/tunables.texi +++ b/manual/tunables.texi @@ -365,8 +365,11 @@ change the main stack permission if kernel starts with a non-executable stack. The @code{glibc.rtld.execstack} can be used to control whether an executable stack is allowed from the main program. Setting the value to @code{0} disables the ABI auto-negotiation (meaning no executable stacks even if the ABI or ELF -header requires it), while @code{1} enables auto-negotiation (although the -program might not need an executable stack). +header requires it), @code{1} enables auto-negotiation (although the program +might not need an executable stack), while @code{2} forces an executable +stack at process start. This is provided for compatibility reasons, when +the program dynamically loads modules with @code{dlopen} which require +an executable stack. When executable stacks are not allowed, and if the main program requires it, the loader will fail with an error message. @@ -380,7 +383,8 @@ of hardware capabilities and kernel configuration. @strong{NB:} Trying to load a dynamic shared library with @code{dlopen} or @code{dlmopen} that requires an executable stack will always fail if the main program does not require an executable stack at loading time. This -is enforced regardless of the tunable value. +can be worked around by setting the tunable to @code{2}, where the stack is +always executable. @end deftp @node Elision Tunables |