fc(1)							      General Commands Manual							     fc(1)

NAME

       fc - Processes the command history list

SYNOPSIS

       fc [-r] [-e editor] [first[last]]

       fc -l  [-nr] [first[last]]

       fc [-s] [old=new] [first]

STANDARDS

       Interfaces documented on this reference page conform to industry standards as follows:

       fc:  XCU5.0

       Refer to the standards(5) reference page for more information about industry standards and associated tags.

OPTIONS

       Uses  the  editor named by editor to edit the commands.	The editor string is a utility name, subject to search via the PATH variable.  The
       value in the FCEDIT variable is used as a default when -e is not specified.  If FCEDIT is null or unset, ed is used as the  editor.   Lists
       the  commands rather than invoking an editor on them.  The commands are written in the sequence indicated by the first and last parameters,
       as affected by -r, with each command preceded by the command number.  Suppresses command numbers when listing with -l.  Reverses the  order
       of the commands listed (with -l) or edited (with neither -l nor -s).  Reexecutes the command without invoking an editor.

OPERANDS

       Selects	the  commands  to  list  or edit.  The number of previous commands that can be accessed is determined by the value of the HISTSIZE
       variable.  The value of first or last or both is one of the following: A positive number representing a command number; command numbers can
       be  displayed with the -l option.  A negative decimal number representing the command that was executed number of commands previously.  For
       example, -1 is the immediately previous command.  A string indicating the most recently entered command that begins with that  string.	If
       the old=new operand is not also specified with -s, the string form of the first operand cannot contain an embedded equal sign.

	      When the synopsis form with -s is used: If first is omitted, the previous command is used.

	      For  the	synopsis  forms  without -s: If last is omitted, last defaults to the previous command when -l is specified; otherwise, it
	      defaults to first.  If first and last are both omitted, the previous 16 commands are listed or the previous single command is edited
	      (based  on  the  -l  option).  If first and last are both present, all of the commands from first to last are edited (without -l) or
	      listed (with -l).  Editing multiple commands is accomplished by presenting to the editor all of the commands at one time, each  com-
	      mand  starting on a new line.  If first represents a newer command than last, the commands are listed or edited in reverse sequence,
	      equivalent to using -r.  For example, the following commands on the first line are equivalent to the corresponding commands  on  the
	      second:

	      fc -r 10 20		     fc    30 40 fc    20 10			fc -r 40 30 When a range of commands is used, it is not an
	      error to specify first or last values that are not in the history list; fc substitutes the value representing the oldest	or  newest
	      command in the list, as appropriate.  For example, if there are only ten commands in the history list, numbered 1 to 10, the follow-
	      ing commands list and edit, respectively, all ten commands:

	      fc -l fc	1 99

	      The first occurrence of string old in the commands to be reexecuted is replaced by the string new.

DESCRIPTION

       The fc utility lists or edits and reexecutes commands previously entered to an interactive shell.

       The command history list references commands by number.	 The first number in the list is selected arbitrarily.	The relationship of a num-
       ber  to	its  command does not change except when the user logs in and no other process is accessing the list, at which time the system may
       reset the numbering to start the oldest retained command at another number (usually 1).	When the number reaches an upper limit, either the
       value  in  HISTSIZE or 32767 (whichever is greater), the shell wraps the numbers, starting the next command with number 1. However, despite
       this optional wrapping of numbers, fc maintains the time-ordering sequence of the commands. For example, if four commands in  sequence  are
       given the numbers 32766, 32767, 1 (wrapped), and 2 as they are executed, command 32767 is considered the command previous to 1, even though
       its number is higher.

       When commands are edited (when the -l option is not specified), the resulting lines are entered at the end of the  history  list  and  then
       reexecuted  by sh.  The fc command that caused the editing is not entered into the history list. If the editor returns a non-zero exit sta-
       tus, this suppresses the entry into the history list and the command reexecution. Any  command-line  variable  assignments  or  redirection
       operators used with fc affect both the fc command itself as well as the command that results.  The following command reinvokes the previous
       command, suppressing standard error for both fc and the previous command: fc -s -- -1 2>/dev/null

NOTES

       Users on windowing systems may want to have  separate  history  files  for  each  window  by  setting  HISTFILE	to  the  following:  HIST-
       FILE=$HOME/.sh_hist$$

RESTRICTIONS

       Since  editors sometimes use file descriptors as integral parts of their editing, redirecting their file descriptors as part of the fc com-
       mand can produce unexpected results.  For example, if vi is the FCEDIT editor, the following command will not work correctly on	many  sys-
       tems: fc -s | more

EXIT STATUS

       The following exit values are returned: Successful completion of the listing.  An error occurred.

       Otherwise, the exit status is that of the commands executed by fc.

ENVIRONMENT VARIABLES

       The following environment variables affect the execution of fc: This variable, when expanded by the shell, determines the default value for
       the -e editor option's editor option-argument.  If FCEDIT is null or unset, ed is used as the editor.  Determines a path name naming a com-
       mand  history file. If the HISTFILE variable is not set, the shell attempts to access or create a file in your home directory. If the shell
       cannot obtain both read and write access to, or create, the history file, it uses a default mechanism that allows the  history  to  operate
       properly.   Changes made to HISTFILE after the history file has been initialized are not effective.  If more than one instance of the shell
       is using the same history file, it is unspecified how updates to the history file from those shells interact. As entries are  deleted  from
       the history file, they will be deleted oldest first.  Determines a decimal number representing the limit to the number of previous commands
       that are accessible. If this variable is unset, a default of 128 is used.  Changes made to HISTSIZE after the history file  has	been  ini-
       tialized  are  not  effective.  Provides a default value for the internationalization variables that are unset or null. If LANG is unset or
       null, the corresponding value from the default locale is used.  If any of the internationalization variables contain  an  invalid  setting,
       the  utility  behaves  as  if  none of the variables had been defined.  If set to a non-empty string value, overrides the values of all the
       other internationalization variables.  Determines the locale for the interpretation of sequences of bytes of text data as  characters  (for
       example, single-byte as opposed to multibyte characters in arguments and input files).  Determines the locale used to affect the format and
       contents of diagnostic messages written to standard error.  Determines the location of message catalogues for  the  processing  of  LC_MES-
       SAGES.

SEE ALSO

       Commands:  sh(1p)

       Standards:  standards(5)

																	     fc(1)