unistd(F)
unistd --
header file for symbolic constants
Synopsis
#include <unistd.h>
Description
The unistd.h header file defines the symbolic constants and
structures not already defined or declared in some
other header file.
The contents of this file are shown below.
The following symbolic constants are defined for the
access function (see
access(S)):
R_OK-
Test for read permission.
W_OK-
Test for write permission.
X_OK-
Test for execute (search) permission.
F_OK-
Test for existence of file.
EFF_ONLY_OK-
Use effective ids instead of real ids.
The constants F_OK, R_OK, W_OK and X_OK
and the expressions
R_OK|W_OK,
R_OK|X_OK
and
R_OK|W_OK|X_OK
all have distinct values.
EFF_ONLY_OK can be ORed with any of these.
unistd declares the constant
NULL-
null pointer
The following symbolic constants are defined for the
lockf(S)
function:
F_ULOCK-
Unlock a previously locked region.
F_LOCK-
Lock a region for exclusive use.
F_TLOCK-
Test and lock a region for exclusive use.
F_TEST-
Test a region for other processes locks.
The following symbolic constants are defined for the
lseek(S)
and
fcntl(S)
functions (they have distinct values):
SEEK_SET-
Set file offset to offset.
SEEK_CUR-
Set file offset to current plus offset.
SEEK_END-
Set file offset to EOF plus offset.
The following symbolic constants are defined (with fixed values):
_POSIX_VERSION-
Integer value indicating version
of the POSIX standard.
_XOPEN_VERSION-
Integer value indicating version of the XPG
to which system is compliant.
The following symbolic constant is defined for the confstr function:
_CS_PATH-
Indicates whether to use the default
PATH environment variable that finds all the standard
utilities.
The following symbolic constants are defined to indicate that the
option is present:
_POSIX_JOB_CONTROL-
Implementation supports job control.
_POSIX_SAVED_IDS-
The
exec(S)
functions
save the effective user and group.
_POSIX_VDISABLE-
Terminal special characters
defined in termios.h (see
termio(HW))
can be
disabled using this character.
The following symbolic constants are defined for version
test macros:
_LFS_LARGEFILE-
Defined to be ``1'' if the implementation supports
the fseeko(S) and ftello(S) functions.
_LFS_ASYNCHRONOUS_IO-
Defined to be ``1'' if the implementation supports
the aio_read(AIO), aio_write(AIO),
and lio_listio(S) functions.
_LFS64_LARGEFILE-
Defined to be ``1'' if the implementation supports
the transitional functions
creat64(S),
fstat64(S),
fstatvfs64(S),
ftruncate64(S),
ftw64(S),
getrlimit64(S),
lockf64(S),
lseek64(S),
lstat64(S),
mmap64(S),
nftw64(S),
open64(S),
readdir64(S),
stat64(S),
setrlimit64(S),
statvfs64(S),
truncate64(S),
_LFS64_ASYNCHRONOUS_IO-
Defined to be ``1'' if the implementation supports
the transitional functions
aio_cancel64(AIO),
aio_error64(AIO),
aio_fsync64(AIO),
aio_read64(AIO),
aio_return64(AIO),
aio_suspend64(AIO),
aio_write64(AIO),
and lio_listio64(S).
_LFS64_STDIO-
Defined to be ``1'' if the implementation supports
the transitional functions
fgetpos64(S),
freopen64(S),
fsetpos64(S),
tmpfile64(S),
fopen64(S),
fseeko64(S),
and ftello64(S),
The following symbolic constants are defined for
sysconf(S):
_SC_ARG_MAX
_SC_CHILD_MAX
_SC_CLK_TCK
_SC_JOB_CONTROL
_SC_LOGNAME_MAX
_SC_NACLS_MAX
_SC_NGROUPS_MAX
_SC_OPEN_MAX
_SC_PAGESIZE
_SC_PASS_MAX
_SC_SAVED_IDS
_SC_VERSION
_SC_XOPEN_VERSION
_SC_TZNAME_MAX
_SC_STREAM_MAX
_SC_XOPEN_SHM
_SC_XOPEN_CRYPT
_SC_XOPEN_ENH_I18N
_SC_2_LOCALDEF
_SC_BC_BASE_MAX
_SC_BC_DIM_MAX
_SC_BC_SCALE_MAX
_SC_BC_STRING_MAX
_SC_COLL_WEIGHTS_MAX
_SC_EXPR_NEST_MAX
_SC_LINE_MAX
_SC_RE_DUP_MAX
_SC_XOPEN_UNIX
_SC_2_VERSION
_SC_2_C_DEV
_SC_2_C_BIND
_SC_2_C_VERSION
_SC_2_CHAR_TERM
_SC_2_FORT_DEV
_SC_2_SW_DEV
_SC_2_UPE
The following symbolic constants are defined for
fpathconf(S):
_PC_CHOWN_RESTRICTED
_PC_FILESIZEBITS
_PC_LINK_MAX
_PC_MAX_CANON
_PC_MAX_INPUT
_PC_NAME_MAX
_PC_NO_TRUNC
_PC_PATH_MAX
_PC_PIPE_BUF
_PC_VDISABLE
The following symbolic constants are defined for file streams:
STDIN_FILENO-
File number of stdin.
It is 0.
STDOUT_FILENO-
File number of stout.
It is 1.
STDERR_FILENO-
File number of stderr.
It is 2.
The following pathnames are defined:
GF_PATH-
Pathname of the group file.
PF_PATH-
Pathname of the passwd file.
References
access(S),
exec(S),
fcntl(S),
fork(S),
fpathconf(S),
group(F),
lseek(S),
passwd(F),
pread(S),
pwrite(S),
sysconf(S),
termio(HW),
termios(S)
Notices
The following values for constants are defined for:
_POSIX_VERSION-
199009L
_POSIX2_VERSION-
199209L
_XOPEN_VERSION-
4
_XOPEN_ENH_I18N-
1
_XOPEN_XPG4-
1
_XOPEN_UNIX-
1
_POSIX2_C_VERSION-
199209L
_XOPEN_XCU_VERSION-
4
© 2005 The SCO Group, Inc. All rights reserved.
SCO OpenServer Release 6.0.0 - 02 June 2005