man > IPC::SysV(3perl)

man perldoc info pydoc3 ri search

📖 NAME

IPC::SysV - System V IPC constants and system calls

🚀 Quick Reference

Use Case	Command	Description
🔑 Generate a SysV IPC key	ftok(PATH, ID)	Create a key from a file path and optional ID for use with msgget, semget, shmget
🔗 Attach shared memory	shmat(ID, ADDR, FLAG)	Attach a shared memory segment to the process address space
🔗 Detach shared memory	shmdt(ADDR)	Detach a shared memory segment from the process address space
📖 Read from shared memory	memread(ADDR, VAR, POS, SIZE)	Read bytes from a memory segment into a variable
✍️ Write to shared memory	memwrite(ADDR, STRING, POS, SIZE)	Write bytes from a string into a memory segment

📝 SYNOPSIS

use IPC::SysV qw(IPC_STAT IPC_PRIVATE);

📘 DESCRIPTION

IPC::SysV defines and conditionally exports all the constants defined in your system include files which are needed by the SysV IPC calls. Common ones include:

IPC_CREAT IPC_EXCL IPC_NOWAIT IPC_PRIVATE IPC_RMID IPC_SET IPC_STAT GETVAL SETVAL GETPID GETNCNT GETZCNT GETALL SETALL SEM_A SEM_R SEM_UNDO SHM_RDONLY SHM_RND SHMLBA

and auxiliary ones:

S_IRUSR S_IWUSR S_IRWXU S_IRGRP S_IWGRP S_IRWXG S_IROTH S_IWOTH S_IRWXO

but your system might have more.

• ftok( PATH [, ID ] ) — Return a key based on PATH and ID, which can be used as a key for msgget, semget and shmget. See ftok(3). If ID is omitted, it defaults to 1. If a single character is given for ID, the numeric value of that character is used.
• shmat( ID, ADDR, FLAG ) — Attach the shared memory segment identified by ID to the address space of the calling process. See shmat(2). ADDR should be undef unless you really know what you're doing.
• shmdt( ADDR ) — Detach the shared memory segment located at the address specified by ADDR from the address space of the calling process. See shmdt(2).
• memread( ADDR, VAR, POS, SIZE ) — Reads SIZE bytes from a memory segment at ADDR starting at position POS. VAR must be a variable that will hold the data read. Returns true if successful, or false if there is an error. memread() taints the variable.
• memwrite( ADDR, STRING, POS, SIZE ) — Writes SIZE bytes from STRING to a memory segment at ADDR starting at position POS. If STRING is too long, only SIZE bytes are used; if STRING is too short, nulls are written to fill out SIZE bytes. Returns true if successful, or false if there is an error.

🔗 SEE ALSO

• IPC::Msg
• IPC::Semaphore
• IPC::SharedMem
• ftok(3)
• shmat(2)
• shmdt(2)

👤 AUTHORS

• Graham Barr <gbarr@pobox.com>
• Jarkko Hietaniemi <jhi@iki.fi>
• Marcus Holland-Moritz <mhx@cpan.org>

©️ COPYRIGHT

Version 2.x, Copyright (C) 2007-2013, Marcus Holland-Moritz.

Version 1.x, Copyright (c) 1997, Graham Barr.

This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

📖 NAME 🚀 Quick Reference 📝 SYNOPSIS 📘 DESCRIPTION 🔗 SEE ALSO 👤 AUTHORS ©️ COPYRIGHT