Visit Our UNIX and Linux User Community

Linux and UNIX Man Pages

Linux & Unix Commands - Search Man Pages

passwd(1) [osx man page]

PASSWD(1)						    BSD General Commands Manual 						 PASSWD(1)

passwd -- modify a user's password SYNOPSIS
passwd [-i infosystem [-l location]] [-u authname] [user] DESCRIPTION
The passwd utility changes the user's password. If the user is not the super-user, passwd first prompts for the current password and will not continue unless the correct password is entered. When entering the new password, the characters entered do not echo, in order to avoid the password being seen by a passer-by. The passwd utility prompts for the new password twice in order to detect typing errors. The new password should be at least six characters long and not purely alphabetic. Its total length should be less than _PASSWORD_LEN (cur- rently 128 characters), although some directory systems allow longer passwords. Numbers, upper case letters, and meta characters are encour- aged. Once the password has been verified, passwd communicates the new password to the directory system. -i infosystem This option specifies where the password update should be applied. Under Mac OS X 10.5 and later, supported directory systems are: PAM (default) Pluggable Authentication Modules. opendirectory A system conforming to Open Directory APIs and supporting updates (including LDAP, etc). If no -l option is specified, the search node is used. file The local flat-files (included for legacy configurations). nis A remote NIS server containing the user's password. -l location This option causes the password to be updated in the given location of the chosen directory system. for file, location may be a file name (/etc/master.passwd is the default) for nis, location may be a NIS domainname for opendirectory, location may be a directory node name for PAM, location is not used -u authname This option specifies the user name to use when authenticating to the directory node. user This optional argument specifies the user account whose password will be changed. This account's current password may be required, even when run as the super-user, depending on the directory system. FILES
/etc/master.passwd The user database /etc/passwd A Version 7 format password file /etc/passwd.XXXXXX Temporary copy of the password file SEE ALSO
chpass(1), login(1), dscl(1), passwd(5), pwd_mkdb(8), vipw(8) Robert Morris and Ken Thompson, UNIX password security. HISTORY
A passwd command appeared in Version 6 AT&T UNIX. Mac OS X August 18, 2008 Mac OS X

Check Out this Related Man Page

PWD_MKDB(8)						    BSD System Manager's Manual 					       PWD_MKDB(8)

pwd_mkdb -- generate the password databases SYNOPSIS
pwd_mkdb [-c] [-p | -s] [-d directory] [-u username] file DESCRIPTION
pwd_mkdb creates db(3) style secure and insecure databases for the specified file. These databases are then installed into /etc/spwd.db and /etc/pwd.db, respectively. The file is installed into /etc/master.passwd. The file must be in the correct format (see passwd(5)). It is important to note that the format used in this system is different from the historic Version 7 style format. The options are as follows: -c Check if the password file is in the correct format. Do not change, add, or remove any files. -d directory Operate in a base directory other than the default of /etc. All absolute paths (including file) will be made relative to directory. Any directories specified as a part of file will be stripped off. This option is used to create password databases in directories other than etc; for instance in a chroot(8) jail. -p Create a Version 7 style password file and install it into /etc/passwd. -s Only update the secure version of the database. This is most commonly used in conjunction with the -u flag during a password change. Because the insecure database doesn't contain the password there is no reason to update it if the only change is in the password field. Cannot be used in conjunction with the -p flag. -u username Only update the record for the specified user. Utilities that operate on a single user can use this option to avoid the overhead of rebuilding the entire database. This option must never be used if the line number of the user's record in /etc/master.passwd has changed. file The absolute path to a file in master.passwd format, as described in passwd(5). The two databases differ in that the secure version contains the user's encrypted password and the insecure version has an asterisk ('*'). The databases are used by the C library password routines (see getpwent(3)). pwd_mkdb exits zero on success, non-zero on failure. FILES
/etc/master.passwd current password file /etc/passwd a Version 7 format password file /etc/pwd.db insecure password database file /etc/pwd.db.tmp temporary file /etc/spwd.db secure password database file /etc/spwd.db.tmp temporary file SEE ALSO
chpass(1), passwd(1), db(3), getpwent(3), passwd(5), vipw(8) STANDARDS
Previous versions of the system had a program similar to pwd_mkdb, mkpasswd, which built dbm(3) style databases for the password file but depended on the calling programs to install them. The program was renamed in order that previous users of the program not be surprised by the changes in functionality. BUGS
Because of the necessity for atomic update of the password files, pwd_mkdb uses rename(2) to install them. This, however, requires that the file specified on the command line live on the same file system as the /etc directory. There are the obvious races with multiple people running pwd_mkdb on different password files at the same time. The front-ends to pwd_mkdb, chpass(1), passwd(1), and vipw(8) handle the locking necessary to avoid this problem. BSD
June 6, 1993 BSD

Featured Tech Videos