Here are the names for the POSIX minimum upper bounds for the system
limit parameters. The significance of these values is that you can
safely push to these limits without checking whether the particular
system you are using can go that far.
_POSIX_AIO_LISTIO_MAX
The most restrictive limit permitted by POSIX for the maximum number of
I/O operations that can be specified in a list I/O call. The value of
this constant is 2; thus you can add up to two new entries
of the list of outstanding operations.
_POSIX_AIO_MAX
The most restrictive limit permitted by POSIX for the maximum number of
outstanding asynchronous I/O operations. The value of this constant is
1. So you cannot expect that you can issue more than one
operation and immediately continue with the normal work, receiving the
notifications asynchronously.
_POSIX_ARG_MAX
The value of this macro is the most restrictive limit permitted by POSIX
for the maximum combined length of the argv and environ
arguments that can be passed to the exec functions.
Its value is 4096.
_POSIX_CHILD_MAX
The value of this macro is the most restrictive limit permitted by POSIX
for the maximum number of simultaneous processes per real user ID. Its
value is 6.
_POSIX_NGROUPS_MAX
The value of this macro is the most restrictive limit permitted by POSIX
for the maximum number of supplementary group IDs per process. Its
value is 0.
_POSIX_OPEN_MAX
The value of this macro is the most restrictive limit permitted by POSIX
for the maximum number of files that a single process can have open
simultaneously. Its value is 16.
_POSIX_SSIZE_MAX
The value of this macro is the most restrictive limit permitted by POSIX
for the maximum value that can be stored in an object of type
ssize_t. Its value is 32767.
_POSIX_STREAM_MAX
The value of this macro is the most restrictive limit permitted by POSIX
for the maximum number of streams that a single process can have open
simultaneously. Its value is 8.
_POSIX_TZNAME_MAX
The value of this macro is the most restrictive limit permitted by POSIX
for the maximum length of a time zone name. Its value is 3.
_POSIX2_RE_DUP_MAX
The value of this macro is the most restrictive limit permitted by POSIX
for the numbers used in the `\{min,max\}' construct
in a regular expression. Its value is 255.
Published under the terms of the GNU General Public License
