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man pages section 8: System Administration Commands

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Updated: Thursday, June 13, 2019
 
 

pwck(8)

Name

pwck, grpck - password/group file checkers

Synopsis

/usr/sbin/pwck [filename]
/usr/sbin/grpck [filename]

Description

pwck scans the password file and notes any inconsistencies. The checks include validation of the number of fields, login name, user ID, group ID, and whether the login directory and the program-to-use-as-shell exist. The default password file is /etc/passwd.

grpck verifies all entries in the group file. This verification includes a check of the number of fields, group name, group ID, whether any login names belong to more than NGROUPS_MAX groups, and that all login names appear in the password file. grpck also issues a warning if it finds an entry (a single line) in the group file longer than 2047 characters. Such an entry causes group maintenance commands, such as groupdel(8) and groupmod(8), to fail.

The default group file is /etc/group.

All messages regarding inconsistent entries are placed on the stderr stream.

Files

  • /etc/group

  • /etc/passwd

Attributes

See attributes(7) for descriptions of the following attributes:

ATTRIBUTE TYPE
ATTRIBUTE VALUE
Availability
system/core-os

See Also

getpwent(3C), group(5), passwd(5), attributes(7), groupdel(8), groupmod(8)

Diagnostics

Group entries in /etc/group with no login names are flagged.

Group file 'filename' is empty

The /etc/passwd or /etc/group file is an empty file.

cannot open file filename: No such file or directory

The /etc/passwd or /etc/group file does not exist.

Notes

If no filename argument is given, grpck checks the local group file, /etc/group, and also makes sure that all login names encountered in the checked group file are known to the system getpwent(3C) routine. This means that the login names may be supplied by a network name service.