Pike Manual

14.1 System

The system module contains some system-specific functions that may or may not be available on your system. Most of these functions do exactly the same thing as their UNIX counterpart. See the UNIX man pages for detailed information about what these functions do on your system.

Please note that these functions are available globally, you do not need to import System to use these functions.

FUNCTION: chroot - change the root directory
SYNTAX: int chroot(string newroot); int chroot(object(File) obj);
DESCRIPTION: Changes the root directory for this process to the indicated directory.
NOTE: Since this function modifies the directory structure as seen from Pike, you have to modify the environment variables PIKE_MODULE_PATH and PIKE_INCLUDE_PATH to compensate for the new root-directory.
This function only exists on systems that have the chroot(2) system call. The second variant only works on systems that also have the fchroot(2) system call.

FUNCTION: getegid - get the effective group ID
SYNTAX: int getegid();
DESCRIPTION: Get the effective group ID.
SEE ALSO: setuid, getuid, setgid, getgid, seteuid, geteuid and setegid

FUNCTION: geteuid - get the effective user ID
SYNTAX: int geteuid();
DESCRIPTION: Get the effective user ID.
SEE ALSO: setuid, getuid, setgid, getgid, seteuid, setegid and getegid

FUNCTION: getgid - get the group ID
SYNTAX: int getgid();
DESCRIPTION: Get the real group ID.
SEE ALSO: setuid, getuid, setgid, seteuid, geteuid, setegid and getegid

FUNCTION: getgroups - get the supplemental group access list
SYNTAX: array(int) getgroups();
DESCRIPTION: Get the current supplemental group access list for this process.
SEE ALSO: initgroups, setgroups, getgid, setgid, getegid and setegid

FUNCTION: gethostbyaddr - gets information about a host given its address
SYNTAX: array gethostbyaddr(string addr);
DESCRIPTION: Returns an array with information about the specified IP address.
The returned array contains the same information as that returned by gethostbyname().
NOTE: This function only exists on systems that have the gethostbyaddr(2) or similar system call.
SEE ALSO: gethostbyname

FUNCTION: gethostbyname - gets information about a host given its name
SYNTAX: array gethostbyname(string hostname);
DESCRIPTION: Returns an array with information about the specified host.
The array contains three elements:
The first element is the hostname.
The second element is an array(string) of IP numbers for the host.
The third element is an array(string) of aliases for the host.
NOTE: This function only exists on systems that have the gethostbyname(2) or similar system call.
SEE ALSO: gethostbyaddr

FUNCTION: gethostname - get the name of this host
SYNTAX: string gethostname();
DESCRIPTION: Returns a string with the name of the host.
NOTE: This function only exists on systems that have the gethostname(2) or uname(2) system calls.

FUNCTION: getpgrp - get the process group ID
SYNTAX: int getpgrp(); int getpgrp(int pid);
DESCRIPTION: With no arguments or with pid equal to zero, returns the process group ID of this process.
If pid is specified, returns the process group ID of that process.
SEE ALSO: getpid and getppid

FUNCTION: getpid - get the process ID
SYNTAX: int getpid();
DESCRIPTION: Returns the process ID of this process.
SEE ALSO: getppid and getpgrp

FUNCTION: getppid - get the parent process ID
SYNTAX: int getppid();
DESCRIPTION: Returns the process ID of the parent process.
SEE ALSO: getpid and getpgrp

FUNCTION: getuid - get the user ID
SYNTAX: int getuid();
DESCRIPTION: Get the real user ID.
SEE ALSO: setuid, setgid, getgid, seteuid, geteuid, setegid and getegid

FUNCTION: hardlink - create a hardlink
SYNTAX: void hardlink(string from, string to);
DESCRIPTION: Creates a hardlink named to from the file from.
SEE ALSO: symlink, mv and rm

FUNCTION: initgroups - initialize the group access list
SYNTAX: void initgroups(string username, int base_gid);
DESCRIPTION: Initializes the group access list according to the system group database. base_gid is also added to the group access list.
SEE ALSO: setuid, getuid, setgid, getgid, seteuid, geteuid, setegid, getegid, getgroups and setgroups

FUNCTION

openlog - initializes the connection to syslogd

SYNTAX

void openlog(string ident, int options, facility);

DESCRIPTION

Initializes the connection to syslogd.

The ident argument specifies an identifier to tag all log entries with.

options is a bit field specifying the behavior of the message logging. Valid options are:

LOG_PID	Log the process ID with each message.
LOG_CONS	Write messages to the console if they can't be sent to syslogd.
LOG_NDELAY	Open the connection to syslogd now and not later.
LOG_NOWAIT	Do not wait for subprocesses talking to syslogd.

facility specifies what subsystem you want to log as. Valid facilities are:

LOG_AUTH	Authorization subsystem
LOG_AUTHPRIV
LOG_CRON	Crontab subsystem
LOG_DAEMON	System daemons
LOG_KERN	Kernel subsystem (NOT USABLE)
LOG_LOCAL	For local use
LOG_LOCAL[1-7]	For local use
LOG_LPR	Line printer spooling system
LOG_MAIL	Mail subsystem
LOG_NEWS	Network news subsystem
LOG_SYSLOG
LOG_USER
LOG_UUCP	UUCP subsystem

NOTE

Only available on systems with syslog(3).

BUGS

LOG_NOWAIT should probably always be specified.

SEE ALSO

syslog, closelog and setlogmask

FUNCTION: readlink - read a symbolic link
SYNTAX: string readlink(string linkname);
DESCRIPTION: Returns what the symbolic link linkname points to.
SEE ALSO: symlink

FUNCTION: setegid - set the effective group ID
SYNTAX: void setegid(int uid);
DESCRIPTION: Sets the effective group ID to gid.
SEE ALSO: setuid, getuid, setgid, getgid, seteuid, geteuid and getegid

FUNCTION: seteuid - set the effective user ID
SYNTAX: void seteuid(int uid);
DESCRIPTION: Sets the effective user ID to uid.
SEE ALSO: setuid, getuid, setgid, getgid, geteuid, setegid and getegid

FUNCTION: setgid - set the group ID
SYNTAX: void setgid(int gid);
DESCRIPTION: Sets the real group ID, effective group ID and saved group ID to gid.
SEE ALSO: setuid, getuid, getgid, seteuid, geteuid, setegid and getegid

FUNCTION: setgroups - set the supplemental group access list
SYNTAX: void getgroups(array(int) gids);
DESCRIPTION: Set the supplemental group access list for this process.
SEE ALSO: initgroups, getgroups, getgid, setgid, getegid and setegid

FUNCTION: setuid - set the user ID
SYNTAX: void setuid(int uid);
DESCRIPTION: Sets the real user ID, effective user ID and saved user ID to uid.
SEE ALSO: getuid, setgid, getgid, seteuid, geteuid, setegid and getegid

FUNCTION: symlink - create a symbolic link
SYNTAX: void symlink(string from, string to);
DESCRIPTION: Creates a symbolic link for an original file from with the new name to.
SEE ALSO: hardlink, readlink, mv and rm

FUNCTION

uname - get operating system information

SYNTAX

mapping(string:string) uname();

DESCRIPTION

Returns a mapping describing the operating system.

The mapping contains the following fields:

"sysname": Operating system name

"nodename": "release": "version": "machine": Host name Release of this OS Version number of this OS Machine architecture

NOTE

This function only exists on systems that have the uname(2) system call.

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	"sysname":	Operating system name
	"nodename": "release": "version": "machine":	Host name Release of this OS Version number of this OS Machine architecture