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ACCT(2) System Calls Manual ACCT(2)


acctenable or disable process accounting


Standard C Library (libc, -lc)


#include <unistd.h>

acct(const char *file);


The () system call enables or disables the collection of system accounting records. If the argument file is a null pointer, accounting is disabled. If file is an pathname (null-terminated), record collection is enabled and for every process initiated which terminates under normal conditions an accounting record is appended to file. Abnormal conditions of termination are reboots or other fatal system problems. Records for processes which never terminate cannot be produced by acct().

For more information on the record structure used by (), see <sys/acct.h> and acct(5).

This call is permitted only to the super-user.


Accounting is automatically disabled when the file system the accounting file resides on runs out of space; it is enabled when space once again becomes available. The values controlling this behaviour can be modified using the following sysctl(8) variables:

Specifies the frequency (in seconds) with which free disk space should be checked.
The percentage of free disk space above which process accounting will resume.
The percentage of free disk space below which process accounting will suspend.


On error -1 is returned. The file must exist and the call may be exercised only by the super-user.


The acct() system call will fail if one of the following is true:

The caller is not the super-user.
A component of the path prefix is not a directory.
A component of a pathname exceeded 255 characters, or an entire path name exceeded 1023 characters.
The named file does not exist.
Search permission is denied for a component of the path prefix, or the path name is not a regular file.
Too many symbolic links were encountered in translating the pathname.
The named file resides on a read-only file system.
The file argument points outside the process's allocated address space.
An I/O error occurred while reading from or writing to the file system.
Corrupted data was detected while reading from the file system.


acct(5), accton(8), sa(8)


The acct() function appeared in Version 7 AT&T UNIX.

March 30, 2020 Debian