script —
make typescript of terminal
session
script |
[-aeFfkqrw] [-t
time] [file
[command ...]] |
script |
-p [-deq]
[-T fmt]
[file] |
The script utility makes a typescript of
everything printed on your terminal. It is useful for students who need a
hardcopy record of an interactive session as proof of an assignment, as the
typescript file can be printed out later with
lpr(1).
If the argument file is given,
script saves all dialogue in
file. If no file name is given, the typescript is
saved in the file typescript.
If the argument command is given,
script will run the specified command with an
optional argument vector instead of an interactive shell.
The following options are available:
-a
- Append the output to file or
typescript, retaining the prior contents.
-d
- When playing back a session with the
-p flag, do
not sleep between records when playing back a timestamped session.
-e
- Accepted for compatibility with
util-linux
script. The child command exit status is always
the exit status of script.
-F
- Immediately flush output after each write. This will allow a user to
create a named pipe using
mkfifo(1) and another user may watch the live session using
a utility like
cat(1).
-f
- Create file.filemon or
typescript.filemon using
filemon(4).
-k
- Log keys sent to the program as well as output.
-p
- Play back a session recorded with the
-r flag in
real time.
-q
- Run in quiet mode, omit the start, stop and command status messages.
-r
- Record a session with input, output, and timestamping.
-t
time
- Specify the interval at which the script output file will be flushed to
disk, in seconds. A value of 0 causes
script to
flush after every character I/O event. The default interval is 30
seconds.
-T
fmt
- Implies
-p, but just reports the time-stamp of
each output. This is very useful for assessing the timing of events.
If fmt does not contain any
‘%’ characters, it indicates the
default format: ‘%n@ %s [%Y-%m-%d
%T]%n’, which is useful for both tools and humans to read,
should be used. Note that time-stamps will only be output when different
from the previous one.
-w
- Forward terminal size changes on
SIGWINCH.
The script ends when the forked shell (or command) exits
(a control-D to exit the POSIX shell
(sh(1)), and
exit,
logout
or control-D (if
ignoreeof
is not set) for the C-shell,
csh(1)).
Certain interactive commands, such as
vi(1), create garbage in the typescript file. The
script utility works best with commands that do not
manipulate the screen. The results are meant to emulate a hardcopy terminal,
not an addressable one.
The following environment variables are utilized by
script:
SCRIPT
- The
SCRIPT environment variable is added to the
sub-shell. If SCRIPT already existed in the users
environment, its value is overwritten within the sub-shell. The value of
SCRIPT is the name of the
typescript file.
SHELL
- If the variable
SHELL exists, the shell forked by
script will be that shell. If
SHELL is not set, the POSIX shell is assumed.
(Most shells set this variable automatically).
Record a simple
csh(1) session with no additional details like input, output,
and timestamping:
$ SHELL=/bin/csh script
Script started, output file is typescript
% date
Tue Jan 5 15:08:10 UTC 2021
% exit
exit
Script done, output file is typescript
Now, replay the session recorded in the previous example:
$ cat ./typescript
Script started on Tue Jan 5 15:08:08 2021
% date
Tue Jan 5 15:08:10 UTC 2021
% exit
exit
Script done on Tue Jan 5 15:08:13 2021
Record a
csh(1) session, but this time with additional details like
timestamping:
$ SHELL=/bin/csh script -r
Script started, output file is typescript
% date
Tue Jan 5 15:17:11 UTC 2021
% exit
exit
Script done, output file is typescript
In order to replay a sessions recorded with the
-r flag, it is necessary to specify
-p
(cat(1) will not work because of all the aditional information
stored in the session file). Also, let us use -d to
print the whole session at once:
$ script -dp ./typescript
Script started on Tue Jan 5 15:17:09 2021
% date
Tue Jan 5 15:17:11 UTC 2021
% exit
exit
Script done on Tue Jan 5 15:17:14 2021
The script command appeared in
3.0BSD.
The -d, -p and
-r options first appeared in NetBSD
2.0 and were ported to FreeBSD 9.2.
The script utility places
everything
in the log file, including linefeeds and backspaces. This is not what the
naive user expects.
It is not possible to specify a command without also naming the
script file because of argument parsing compatibility issues.
When running in -k mode, echo cancelling
is far from ideal. The slave terminal mode is checked for ECHO mode to check
when to avoid manual echo logging. This does not work when the terminal is
in a raw mode where the program being run is doing manual echo.
If script reads zero bytes from the
terminal, it switches to a mode when it only attempts to read once a second
until there is data to read. This prevents script
from spinning on zero-byte reads, but might cause a 1-second delay in
processing of user input.