string.3: Add short description of the functions

It is helpful to have a short description about what the different
functions in string.h do.

Signed-off-by: Moritz 'Morty' Strübe <morty@gmx.net>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
string.3: Fixes and enhancements to Moritz Str?be's patch

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
strsep.3: Clarify description

The use of "symbols" in the existing description is confusing;
it's "bytes". Other fixes as well.

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
strstr.3: Clarify RETURN VALUE: s/substring/located substring/

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
packet.7: Document fanout, ring, and auxiliary options

The packet socket manual page does not list all socket options.

This patch adds descriptions of the common packet socket options
  PACKET_AUXDATA, PACKET_FANOUT, PACKET_RX_RING, PACKET_STATISTICS,
  PACKET_TX_RING

and the ring-specific options
  PACKET_LOSS, PACKET_RESERVE, PACKET_TIMESTAMP, PACKET_VERSION

It does not yet add descriptions for
  PACKET_COPY_THRESH, PACKET_HDRLEN, PACKET_ORIGDEV,
  PACKET_TX_HAS_OFF, PACKET_TX_TIMESTAMP, PACKET_VNET_HDR

It tries to balance being informative with exposing kernel detail
that is unlikely to be used by most readers or that may change
frequently. For implementation details, the manpage points to the
documentation in kernel Documentation/networking. Let me know if
options should be added or removed.

Source: PACKET_FANOUT, PACKET_RX_RING and PACKET_VERSION are in
/tools/testing/net/psock_fanout.c in the latest Linux kernel source
tree. PACKET_STATISTICS was in the first version of that test.
PACKET_TX_RING I have used elsewhere. The other options are based
on reading kernel code.

 [Very minor fixups. -dborkman]

Acked-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
packet.7: Minor fixes

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
packet.7: Add kernel version numbers for PACKET_VERSION and PACKET_TIMESTAMP

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
packet.7: wfix: s/network order/network byte order/

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
get_mempolicy.2, mbind.2, mlock.2, set_mempolicy.2, bootparam.7, packet.7: grfix: s/memory mapped/memory-mapped/ when used attributively

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
rtime.3: ffix

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
rtime.3: Add "static" qualifier to global variable in example program

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
stpcpy.3: ffix

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
strftime.3: Add "Program source" subsection heading

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
tsearch.3: Add "static" to global variables and functions in example program

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
perf_event_open.2: Add "static" qualifier to function in example program

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
getsubopt.3: ffix (K&R style in example program)

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
hsearch.3: Add "static" to global variable in example program

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
rtime.3: ffix

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
mprotect.2: Add "static" to global variable in example program

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
chown.2, clone.2, mmap.2, pipe.2, ftw.3, mq_notify.3: Add "Program source" subheading under EXAMPLE

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>