history(1) User Commands history(1)NAME
history, fc, hist - process command history list
SYNOPSIS
/usr/bin/fc [-r] [-e editor] [first [last]]
/usr/bin/fc -l [-nr] [first [last]]
/usr/bin/fc -s [old=new] [first]
csh
history [-hr] [n]
ksh
fc -e - [old=new] [command]
fc -s [old = new] [command]
fc [-e ename] [-nlr] [first [last]]
ksh93
hist [-lnprs] [-e editor][-N num][first[last]]
DESCRIPTION
/usr/bin/fc
The fc utility lists or edits and reexecutes, commands previously
entered to an interactive sh.
The command history list references commands by number. The first num‐
ber in the list is selected arbitrarily. The relationship of a number
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 can reset
the numbering to start the oldest retained command at another number
(usually 1). When the number reaches the value in HISTSIZE or 32767
(whichever is greater), the shell can wrap the numbers, starting the
next command with a lower number (usually 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 32 766, 32 767, 1 (wrapped), and 2 as they are executed,
command 32 767 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 is 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 status,
this suppresses the entry into the history list and the command reexe‐
cution. Any command-line variable assignments or redirection operators
used with fc affects both the fc command itself as well as the command
that results, for example:
fc -s -- -1 2>/dev/null
reinvokes the previous command, suppressing standard error for both fc
and the previous command.
csh
Display the history list. If n is given, display only the n most recent
events.
-r Reverse the order of printout to be most recent first rather than
oldest first.
-h Display the history list without leading numbers. This is used to
produce files suitable for sourcing using the -h option to the
csh built-in command, source(1).
History Substitution:
History substitution allows you to use words from previous command
lines in the command line you are typing. This simplifies spelling cor‐
rections and the repetition of complicated commands or arguments. Com‐
mand lines are saved in the history list, the size of which is con‐
trolled by the history variable. The history shell variable can be set
to the maximum number of command lines that is saved in the history
file, that is:
set history = 200
allows the history list to keep track of the most recent 200 command
lines. If not set, the C shell saves only the most recent command.
A history substitution begins with a ! (although you can change this
with the histchars variable) and can occur anywhere on the command
line; history substitutions do not nest. The ! can be escaped with \ to
suppress its special meaning.
Input lines containing history substitutions are echoed on the terminal
after being expanded, but before any other substitutions take place or
the command gets executed.
Event Designators:
An event designator is a reference to a command line entry in the his‐
tory list.
!
Start a history substitution, except when followed by a space char‐
acter, tab, newline, = or (.
!!
Refer to the previous command. By itself, this substitution repeats
the previous command.
!n
Refer to command line n.
!-n
Refer to the current command line minus n.
!str
Refer to the most recent command starting with str.
!?str?
Refer to the most recent command containing str.
!?str? additional
Refer to the most recent command containing str and append addi‐
tional to that referenced command.
!{command} additional
Refer to the most recent command beginning with command and append
additional to that referenced command.
^previous_word^replacement^
Repeat the previous command line replacing the string previous_word
with the string replacement. This is equivalent to the history sub‐
stitution:
Repeat the previous command line replacing the string previous_word
with the string replacement. This is equivalent to the history sub‐
stitution:
!:s/previous_word/replacement/.
To re-execute a specific previous command and make such a substitu‐
tion, say, re-executing command #6:
!:6s/previous_word/replacement/.
Word Designators:
A `:' (colon) separates the event specification from the word designa‐
tor. 2It can be omitted if the word designator begins with a ^, $, *, −
or %. If the word is to be selected from the previous command, the sec‐
ond ! character can be omitted from the event specification. For
instance, !!:1 and !:1 both refer to the first word of the previous
command, while !!$ and !$ both refer to the last word in the previous
command. Word designators include:
# The entire command line typed so far.
0 The first input word (command).
n The n'th argument.
^ The first argument, that is, 1.
$ The last argument.
% The word matched by (the most recent) ?s search.
x−y A range of words; −y abbreviates 0−y.
* All the arguments, or a null value if there is just one word
in the event.
x* Abbreviates x−$.
x− Like x* but omitting word $.
Modifiers:
After the optional word designator, you can add a sequence of one or
more of the following modifiers, each preceded by a :.
h Remove a trailing pathname component, leav‐
ing the head.
r Remove a trailing suffix of the form
`.xxx', leaving the basename.
e Remove all but the suffix, leaving the
extension.
s/oldchars/replacements/ Substitute replacements for oldchars. old‐
chars is a string that can contain embedded
blank spaces, whereas previous_word in the
event designator can not.
^oldchars^replacements^
t Remove all leading pathname components,
leaving the tail.
& Repeat the previous substitution.
g Apply the change to the first occurrence of
a match in each word, by prefixing the
above (for example, g&).
p Print the new command but do not execute
it.
q Quote the substituted words, escaping fur‐
ther substitutions.
x Like q, but break into words at each space
character, tab or newline.
Unless preceded by a g, the modification is applied only to the first
string that matches oldchars. An error results if no string matches.
The left-hand side of substitutions are not regular expressions, but
character strings. Any character can be used as the delimiter in place
of /. A backslash quotes the delimiter character. The character &, in
the right hand side, is replaced by the text from the left-hand-side.
The & can be quoted with a backslash. A null oldchars uses the previous
string either from a oldchars or from a contextual scan string s from
!?s. You can omit the rightmost delimiter if a newline immediately fol‐
lows replacements; the rightmost ? in a context scan can similarly be
omitted.
Without an event specification, a history reference refers either to
the previous command, or to a previous history reference on the command
line (if any).
ksh
Using fc, in the form of
fc -e − [old=new] [command],
or
fc -s [old=new] [command],
the command is re-executed after the substitution old=new is performed.
If there is not a command argument, the most recent command typed at
this terminal is executed.
Using fc in the form of
fc [-e ename] [-nlr ] [first [last]],
a range of commands from first to last is selected from the last HIST‐
SIZE commands that were typed at the terminal. The arguments first and
last can be specified as a number or as a string. A string is used to
locate the most recent command starting with the given string. A nega‐
tive number is used as an offset to the current command number. If the
-l flag is selected, the commands are listed on standard output. Other‐
wise, the editor program -e name is invoked on a file containing these
keyboard commands. If ename is not supplied, then the value of the
variable FCEDIT (default /bin/ed) is used as the editor. When editing
is complete, the edited command(s) is executed. If last is not speci‐
fied, it is set to first. If first is not specified, the default is the
previous command for editing and −16 for listing. The flag -r reverses
the order of the commands and the flag -n suppresses command numbers
when listing. (See ksh(1) for more about command line editing.)
HISTFILE If this variable is set when the shell is invoked, then the
value is the pathname of the file that is used to store the
command history.
HISTSIZE If this variable is set when the shell is invoked, then the
number of previously entered commands that are accessible
by this shell is greater than or equal to this number. The
default is 128.
Command Re-entry:
The text of the last HISTSIZE (default 128) commands entered from a
terminal device is saved in a history file. The file $HOME/.sh_history
is used if the HISTFILE variable is not set or if the file it names is
not writable. A shell can access the commands of all interactive shells
which use the same named HISTFILE. The special command fc is used to
list or edit a portion of this file. The portion of the file to be
edited or listed can be selected by number or by giving the first char‐
acter or characters of the command. A single command or range of com‐
mands can be specified. If you do not specify an editor program as an
argument to fc then the value of the variable FCEDIT is used. If FCEDIT
is not defined then /bin/ed is used. The edited command(s) is printed
and re-executed upon leaving the editor. The editor name − is used to
skip the editing phase and to re-execute the command. In this case a
substitution parameter of the form old=new can be used to modify the
command before execution. For example, if r is aliased to a´fc -e − a´
then typing `r bad=good c' re-executes the most recent command which
starts with the letter c, replacing the first occurrence of the string
bad with the string good.
Using the fc built-in command within a compound command causes the
whole command to disappear from the history file.
ksh93
hist lists, edits, or re-executes commands previously entered into the
current shell environment.
The command history list references commands by number. The first num‐
ber in the list is selected arbitrarily. The relationship of a number
to its command does not change during a login session. When the number
reaches 32767 the number wraps around to 1 but maintains the ordering.
When the l option is not specified, and commands are edited, the
resulting lines are entered at the end of the history list and then re-
executed by the current shell. The hist command that caused the editing
is not entered into the history list. If the editor returns a non-zero
exit status, this suppresses the entry into the history list and the
command re-execution. Command line variable assignments and redirec‐
tions affect both the hist command and the commands that are re-exe‐
cuted.
first and last define the range of commands. Specify first and last as
one of the following:
number A positive number representing a command number. A + sign
can precede number.
-number A negative number representing a command that was executed
number commands previously. For example, -1 is the previous
command.
string string indicates the most recently entered command that
begins with string. string should not contain an =.
If first is omitted, the previous command is used, unless -l is speci‐
fied, in which case it defaults to -16 and last defaults to -1.
If first is specified and last is omitted, then last defaults to first
unless -l is specified in which case it defaults to -1.
If no editor is specified, then the editor specified by the HISTEDIT
variable is used if set, or the FCEDIT variable is used if set, other‐
wise, ed is used.
OPTIONS
The following options are supported:
-e editor 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.
-l (The letter ell.) Lists the commands rather than invoking
an editor on them. The commands is written in the sequence
indicated by the first and last operands, as affected by
-r, with each command preceded by the command number.
-n Suppresses command numbers when listing with -l.
-r Reverses the order of the commands listed (with -l ) or
edited (with neither -l nor -s).
-s Re-executes the command without invoking an editor.
ksh93
ksh93 supports the following options:
-e editor Specify the editor to use to edit the history command. A
value of - for editor is equivalent to specifying the -s
option.
-l List the commands rather than editing and re-executing
them.
-N num Start at num commands back.
-n Suppress the command numbers when the commands are listed.
-p Write the result of history expansion for each operand to
standard output. All other options are ignored.
-r Reverse the order of the commands.
-s Re-execute the command without invoking an editor. In this
case an operand of the form old=new can be specified to
change the first occurrence of the string old in the com‐
mand to new before re-executing the command.
OPERANDS
The following operands are supported:
first Selects the commands to list or edit. The number of previous
last 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:
[+]number A positive number representing a command number.
Command numbers can be displayed with the -l
option.
−number A negative decimal number representing the com‐
mand that was executed number of commands previ‐
ously. For example, −1 is the immediately previ‐
ous command.
string 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 con‐
tain 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 :
o If last is omitted, last defaults to
the previous command when -l is spec‐
ified; otherwise, it defaults to
first.
o If first and last are both omitted,
the previous 16 commands is listed or
the previous single command is edited
(based on the -l option).
o If first and last are both present,
all of the commands from first to
last is edited (without -l ) or
listed (with -l). Editing multiple
commands is accomplished by present‐
ing to the editor all of the commands
at one time, each command starting on
a new line. If first represents a
newer command than last, the commands
is 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
o When a range of commands is used, it
is not be an error to specify first
or last values that are not in the
history list. fc substitutes the
value representing the oldest or new‐
est command in the list, as appropri‐
ate. For example, if there are only
ten commands in the history list,
numbered 1 to 10:
fc -l
fc 1 99
lists and edits, respectively, all
ten commands.
old=new Replace the first occurrence of string old in
the commands to be reexecuted by the string new.
OUTPUT
When the -l option is used to list commands, the format of each command
in the list is as follows:
"%d\t%s\n", <line number>, <command>
If both the -l and -n options are specified, the format of each command
is:
"\t%s\n", <command>
If the commandcommand consists of more than one line, the lines after
the first are displayed as:
"\t%s\n", <continued-command>
EXAMPLES
Example 1 Using history and fc
csh ksh
% history $ fc -l
1 cd /etc 1 cd /etc
2 vi passwd 2 vi passwd
3 date 3 date
4 cd 4 cd
5 du . 5 du .
6 ls -t 6 ls -t
7 history 7 fc -l
% !d $ fc -e - d
du . du .
262 ./SCCS 262 ./SCCS
336 . 336 .
% !da $ fc -e - da
Thu Jul 21 17:29:56 PDT 1994 Thu Jul 21 17:29:56 PDT 1994
% $ alias \!='fc -e -'
% !! $ !
date alias ='fc -e -'
Thu Jul 21 17:29:56 PDT 1994
ENVIRONMENT VARIABLES
See environ(5) for descriptions of the following environment variables
that affect the execution of fc: LC_CTYPE, LC_MESSAGES, and NLSPATH.
FCEDIT 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(1) is used as the
editor.
HISTFILE Determine a pathname naming a command history file. If the
HISTFILE variable is not set, the shell can attempt to
access or create a file .sh_history in the user's home
directory. If the shell cannot obtain both read and write
access to, or create, the history file, it uses an unspeci‐
fied mechanism that allows the history to operate properly.
(References to history ``file'' in this section are under‐
stood to mean this unspecified mechanism in such cases.) fc
can choose to access this variable only when initializing
the history file; this initialization occurs when fc or sh
first attempt to retrieve entries from, or add entries to,
the file, as the result of commands issued by the user, the
file named by the ENV variable, or a system startup file
such as /etc/profile. (The initialization process for the
history file can be dependent on the system startup files,
in that they can contain commands that effectively preempts
the user's settings of HISTFILE and HISTSIZE. For example,
function definition commands are recorded in the history
file, unless the set -o nolog option is set. If the system
administrator includes function definitions in some system
startup file called before the ENV file, the history file
is initialized before the user gets a chance to influence
its characteristics.) The variable HISTFILE is accessed
initially when the shell is invoked. Any changes to HIST‐
FILE does not take effect until another shell is invoked.
HISTSIZE Determine a decimal number representing the limit to the
number of previous commands that are accessible. If this
variable is unset, an unspecified default greater than or
equal to 128 are used. The variable HISTSIZE is accessed
initially when the shell is invoked. Any changes to HIST‐
SIZE does not take effect until another shell is invoked.
EXIT STATUS
The following exit values are returned:
0 Successful completion of the listing.
>0 An error occurred.
Otherwise, the exit status is that of the commands executed by fc or
hist.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
┌─────────────────────────────┬─────────────────────────────┐
│ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
├─────────────────────────────┼─────────────────────────────┤
│Availability │SUNWcs │
└─────────────────────────────┴─────────────────────────────┘
SEE ALSOcsh(1), ed(1), ksh(1), ksh93(1), set(1), set(1F), sh(1), source(1),
attributes(5), environ(5)SunOS 5.11 2 Nov 2007 history(1)