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su(1)
NAME
  su - Substitutes user ID temporarily

SYNOPSIS
  su [- | -f] [user] [shell_option] [shell_command]

OPTIONS
  -f  Prevents the user's shell initialization file from being executed by
      passing the -f option to the user's shell, thus making su start up
      faster. The -f option is supported by the csh family of shells.

  -   Simulates a full login by executing the commands in either the .cshrc
      and .login files for csh or the .profile file for sh and ksh and by
      setting the current working directory to the user's home directory.

  shell_option
      Passes the specified shell option flag to the newly invoked user's
      shell for execution. The shell_option must be supported by the invoked
      shell. The csh, sh, ksh, and any other interactive command shell
      support the commonly used -c shell option. By default (no
      "shell_option"), the shell is opened with the -i (interactive) shell
      option. See the reference page for the shell you are using for more
      information on the shell options.

  shell_command
      Passes the specified command to the newly invoked user's shell for
      execution.  The shell_command must be supported by the invoked shell.

DESCRIPTION
  The su command demands the password of the specified user, and if it is
  given, changes to that user and invokes the user's shell without changing
  the current directory.

  Except in a case where the - option is used, the user environment is
  unchanged except for HOME, SHELL, USER, and LOGNAME which are taken from
  the password file for the user being substituted (see environ).  The new
  user ID stays in force until the shell exits.

  If no user is specified, root is assumed.  Only users who belong to group
  number 0 (system) can issue su to become root, even with the root password.
  To remind superusers of their responsibilities, the shell substitutes a #
  (number sign) for its usual prompt.

  Shell commands may be passed to the shell that is spawned by su by
  including them on the command line after the su flags and arguments. After
  the flags recognized by su and the user argument are processed,
  unrecognized command line flags (shell_options) and/or arguments
  (shell_commands) are passed to the shell for execution. If the spawned
  shell does not support the command or the format of the command, the
  command is not executed and the resulting shell behavior and error messages
  are determined by the shell.





  Security Restrictions


  The su command fails if any lock conditions exist on the target account.
  Specifically, if the destination account was retired, if the number of
  unsuccessful login attempts exceeds the maximum allowed, if the
  administrative lock was applied, or the password's lifetime was exceeded,
  the Information System Security Officer (ISSO) must unlock the destination
  account before any user can log in to it or use su to transition to it.

SECURITY NOTE
  This security-sensitive command uses SIA (Security Integration
  Architecture) as an interface to the security mechanism(s) that perform the
  actual user validation. See the matrix.conf(4) reference page for more
  information.

ENVIRONMENT VARIABLES
  The following environment variables affect the behavior of su:

SEE ALSO
  Commands:  csh(1), ksh(1), sh(1)

Index for Section 1

Alphabetical listing for S

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