- _SC_ARG_MAX
Stands for ARG_MAX defined in <limits.h> -- the
maximum number of bytes of arguments and environment
data that can be passed in an exec() call.
- _SC_BC_BASE_MAX
Stands for BC_BASE_MAX defined in <unistd.h> -- the
maximum value for ibase and obase in bc(1).
- _SC_BC_DIM_MAX
Stands for BC_DIM_MAX defined in <unistd.h> -- the
maximum number of elements in a bc(1) array.
- _SC_BC_SCALE_MAX
Stands for BC_SCALE_MAX defined in <unistd.h> -- the
maximum scale in bc(1).
- _SC_BC_STRING_MAX
Stands for BC_STRING_MAX defined in <unistd.h> -- the
maximum length of a string accepted by bc(1).
- _SC_CHILD_MAX
Stands for CHILD_MAX defined in <limits.h> -- the
maximum number of processes that a real user ID may
have executing simultaneously.
- _SC_CLK_TCK
Stands for CLK_TCK defined in <time.h> -- the number
of clock ticks in a second.
- _SC_COLL_WEIGHTS_MAX
Stands for COLL_WEIGHTS_MAX defined in <unistd.h> --
the maximum number of weights that can be assigned to
an entry of the LC_COLLATE order keyword in the locale
definition file.
- _SC_EXPR_NEST_MAX
Stands for EXPR_NEST_MAX defined in <unistd.h> -- the
largest number of expressions that can be nested within
parentheses by expr(1).
- _SC_JOB_CONTROL
Stands for _POSIX_JOB_CONTROL which may be defined in
<unistd.h> -- this indicates that certain job control
operations are implemented by this version of the
operating system. If _POSIX_JOB_CONTROL is defined,
various functions (for example, setpgid()) have greater
functionality than when it is not defined.
- _SC_LINE_MAX
Stands for LINE_MAX defined in <unistd.h> -- the
maximum length of a utility's input line when the
utility processes text files. This length includes the
newline on the end of the line.
- _SC_NGROUPS_MAX
Stands for NGROUPS_MAX defined in <limits.h> -- the
maximum number of supplementary group IDs that may be
associated with a process.
- _SC_OPEN_MAX
Stands for OPEN_MAX defined in <limits.h> -- the
maximum number of files that a single process may have
open at one time.
- _SC_RE_DUP_MAX
Stands for RE_DUP_MAX defined in <unistd.h> -- the largest number of repeated occurrences of a regular expression that you can use in the notation \{m,n\}.
- _SC_SAVED_IDS
Stands for _POSIX_SAVED_IDS which may be defined in
<unistd.h> -- this indicates that this POSIX
implementation has a saved set-user-ID and a saved set-
group-ID. This affects the behavior of functions like
setuid() and setgid().
- _SC_STREAM_MAX
Stands for _POSIX_STREAM_MAX which may be defined in <limits.h> -- the number of streams that one process can have open at one time.
- _SC_TZNAME_MAX
Stands for _POSIX_TZNAME_MAX which may be defined in
<limits.h> -- the maximum number of bytes supported
for the name of a time zone (not of the TZ variable).
- _SC_VERSION
Stands for _POSIX_VERSION which may be defined in <unistd.h> -- this indicates the version of the POSIX.1 standard to which the system conforms.
- _SC_2_C_BIND
Stands for _POSIX2_C_BIND which may be defined in <unistd.h> -- if this is defined, the system supports the C Language Bindings Option of POSIX.2.
- _SC_2_C_DEV
Stands for _POSIX2_C_DEV which may be defined in <unistd.h> -- if this is defined, the system supports the C Language Development Utilities Option of POSIX.2.
- _SC_2_CHAR_TERM
Stands for _POSIX2_CHAR_TERM which may be defined in <unistd.h> -- if this is defined, the system supports at least one terminal type capable of all operations necessary for the User Portability Utilities. This is only on if _SC_2_UPE is on.
- _SC_2_FORT_DEV
Stands for _POSIX2_FORT_DEV which may be defined in <unistd.h> -- if this is defined, the system supports the FORTRAN Development Utilities Option of POSIX.2.
- _SC_2_FORT_RUN
Stands for _POSIX2_FORT_RUN which may be defined in <unistd.h> -- if this is defined, the system supports the FORTRAN Runtime Utilities Option of POSIX.2.
- _SC_2_LOCALEDEF
Stands for _POSIX2_LOCALEDEF which may be defined in <unistd.h> -- if this is defined, the system supports the creation of locales.
- _SC_2_SW_DEV;
Stands for _POSIX2_SW_DEV which may be defined in <unistd.h> -- if this is defined, the system supports the Software Development Utilities Option of POSIX.2.
- _SC_2_UPE
Stands for _POSIX2_UPE which may be defined in <unistd.h> -- if this is defined, the system supports the User Portability Utilities Option.
- _SC_2_VERSION
Stands for _POSIX2_VERSION which may be defined in <unistd.h> -- this indicates the version of the POSIX.2 standard to which the system conforms.
