XSI_SINGLE_PROCESS

XSI Single Process option group. More...

Files
file	time.h
	POSIX time-of-day types and functions (<sys/time.h>)

Macros
#define	P_tmpdir   "/tmp"
	Pathname of the directory for temporary files.

Functions
char *	ctermid (char *s)
	Maximum number of streams that one process can have open at one time.
int	pclose (FILE *stream)
	Close a pipe stream.
FILE *	popen (const char *command, const char *type)
	Create a pipe to a process.
char *	tempnam (const char *dir, const char *pfx)
	Generate a pathname for a temporary file (obsolescent).
int	putenv (char *string)
	Add or change an environment variable (XSI extension).
int	gettimeofday (struct timeval *tv, void *tz)
	Get the current time with microsecond resolution.
char *	crypt (const char *key, const char *salt)
	Encrypt a password string (XSI extension, not recommended for new code).
void	encrypt (char block[64], int edflag)
	Encrypt or decrypt a 64-bit block using DES (XSI extension).
long	gethostid (void)
	Get a unique identifier for the host system (XSI extension).

Detailed Description

XSI Single Process option group.

Covers gethostid(), gettimeofday(), putenv(), and related XSI-mandatory single-process functions.

Macro Definition Documentation

P_tmpdir

#define P_tmpdir   "/tmp"

Pathname of the directory for temporary files.

See also

https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/stdio.h.html

Definition at line 67 of file posix_stdio.h.

Function Documentation

crypt()

char * crypt	(	const char *	key,
		const char *	salt
	)

Encrypt a password string (XSI extension, not recommended for new code).

See also

https://pubs.opengroup.org/onlinepubs/9699919799/functions/crypt.html

ctermid()

char * ctermid

(

char *

s

)

Maximum number of streams that one process can have open at one time.

See also

https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/stdio.h.html

Generate a pathname for the controlling terminal.

Parameters

s	Optional buffer of at least L_ctermid bytes, or NULL.

Returns

Pathname of the controlling terminal, or NULL on failure.

See also

https://pubs.opengroup.org/onlinepubs/9699919799/functions/ctermid.html

encrypt()

void encrypt	(	char	block[64],
		int	edflag
	)

Encrypt or decrypt a 64-bit block using DES (XSI extension).

See also

https://pubs.opengroup.org/onlinepubs/9699919799/functions/encrypt.html

gethostid()

long gethostid

(

void

)

Get a unique identifier for the host system (XSI extension).

See also

https://pubs.opengroup.org/onlinepubs/9699919799/functions/gethostid.html

gettimeofday()

int gettimeofday	(	struct timeval *	tv,
		void *	tz
	)

Get the current time with microsecond resolution.

Parameters

tv	Output: current time; tv_sec is seconds and tv_usec is microseconds since the Epoch.
tz	Deprecated, must be NULL.

Returns

0 on success, or -1 with errno set on failure.

See also

https://pubs.opengroup.org/onlinepubs/9699919799/functions/gettimeofday.html

pclose()

int pclose

(

FILE *

stream

)

Close a pipe stream.

Parameters

stream

Stream returned by popen().

Returns

Termination status of the command, or -1 on failure.

See also

https://pubs.opengroup.org/onlinepubs/9699919799/functions/pclose.html

popen()

FILE * popen	(	const char *	command,
		const char *	type
	)

Create a pipe to a process.

Parameters

command	Shell command to execute.
type	"r" to read from the command, or "w" to write to it.

Returns

Pointer to the stream, or NULL on failure.

See also

https://pubs.opengroup.org/onlinepubs/9699919799/functions/popen.html

putenv()

int putenv

(

char *

string

)

Add or change an environment variable (XSI extension).

string must be of the form "NAME=value". The string is placed directly in the environment, so it must remain valid for the lifetime of the process.

Parameters

string

Environment entry of the form "NAME=value".

Returns

0 on success, or -1 with errno set on failure.

See also

https://pubs.opengroup.org/onlinepubs/9699919799/functions/putenv.html

tempnam()

char * tempnam	(	const char *	dir,
		const char *	pfx
	)

Generate a pathname for a temporary file (obsolescent).

Parameters

dir	Directory prefix, or NULL to use P_tmpdir.
pfx	Filename prefix, or NULL.

Returns

Pointer to a pathname, or NULL on failure.

See also

https://pubs.opengroup.org/onlinepubs/9699919799/functions/tempnam.html