netdb: implement getnetbynane and getnetent

See merge request !278

This patch implements getnetbyname and getnetent functions.

Scanf

See merge request !277

This is the behavior of glibc which I assume to be right

The LookAheadReader api works similar to read but it has 2 methods,
lookahead: it will read 1 byte (with internal ftell) without modifying
the file's own ftell() and commit() which saves the current file ftell

LookAheadReader can wrap both buffers and files

FIX error: right operand of shift expression '(1 << BLA)' is greater than or...

See merge request !276

no name authored 4 years ago and Ahmed Abd El Mawgood committed 4 years ago

FIX error: right operand of shift expression '(1 << BLA)' is greater than or equal to the precision BLA of the left operand [-fpermissive]

Ld library path

See merge request !275

During early parts of ld.so, errno and other thread local variables are
not yet initialized so we cannot use function (such as unistd::access)
that depends on such thread local variables (errno). For this reason
this patch creates small wrapper around the syscall that doesn't not
touch the errno

Current LD_LIBRARY_PATH implementation overwrites the original search
path, which is not the best idea, instead this patch would check
LD_LIBRARY_PATH first and if it didn't find the libraries it is looking
for, then it will search the original search path

Don't accept null pointer in tests when requesting aligned memory

See merge request !272

Minor fixes to posix_memalign()

See merge request !271

Gcc regressions

See merge request !270

as it seams you can do something like
        printf ("A%*s%s/\n", -5, "B", "CC");
and it will print the padding to the left

Scanf function requires look ahead to function properly, In case of
scanning from a buffer that will not be an issue, but in our case we are
reading from file, so lookaheads needs to be undone (via lseek) in our
case. The only problem here is that if we opened a file that doesn't
support lseek such as many of the file /dev/*

At least in relibc, each call to ungetc should decrement ftell() by one
also allowing negative ftell() this is not possible on relibc thus gcc
failing to compile (gcc compiles tools that is later used to compile gcc
itself and these tools are the ones that fail)

According to the standards, only one ungetc may be guaranteed however
glibc allows more than one of those, and to be glibc compatiable, one
needs to be able to do the same, allowing only 1 ungetc may trigger bug
while compiling gcc as ungetc is used there alot

Normally one shouldn't be using this datatype ever, but then someone
have to tell that to gcc folks :(