shmsegsz

Shmsegsz is a system call in Unix-like operating systems that is used to set the maximum size of shared memory segments. Shared memory is a mechanism that allows multiple processes to access the same memory space, facilitating efficient inter-process communication (IPC). The shmsegsz system call is typically used by system administrators or applications that require fine-grained control over shared memory resources.

The shmsegsz system call takes a single argument, which is the new maximum size for shared memory segments. This size is specified in bytes. The call returns 0 on success, indicating that the maximum size has been successfully updated. If the call fails, it returns -1, and the errno variable is set to indicate the error.

The shmsegsz system call is part of the System V IPC (Inter-Process Communication) set of calls, which also includes shmget, shmat, shmdt, and shmctl. These calls provide a standardized way for processes to share data and synchronize their operations.

The shmsegsz system call is not commonly used in modern applications, as the POSIX shared memory API (shm_open, shm_unlink, etc.) provides a more flexible and portable alternative. However, it remains an important tool for system administrators and legacy applications that rely on the System V IPC mechanism.