Bash/scripts - Revision history

Christoph: /* Run a local script on a remote host */

2021-09-21T22:38:10Z

‎Run a local script on a remote host

Christoph: /* Functions */

2021-09-21T22:37:37Z

‎Functions

Christoph: /* Brace expansion */

2012-05-30T21:03:45Z

‎Brace expansion

Christoph: /* Brace expansion */

2012-05-30T20:11:30Z

‎Brace expansion

Christoph: /* Brace expansion */

2012-05-30T20:06:47Z

‎Brace expansion

Christoph: /* Brace expansion */

2007-08-25T08:52:06Z

‎Brace expansion

Christoph at 08:49, 25 August 2007

2007-08-25T08:49:05Z

Christoph at 08:29, 25 August 2007

2007-08-25T08:29:11Z

New page

==History functions==
history # display history for current tty
!! # repeat last command
!foo # repeat last command starting with 'foo'
!N # execute command number N from history output
!foo:p # _show_ last command starting with 'foo' but do _not_ execute it
!-N$:p # _show_ N-commands ago but do _not_ execute it
!$ # grab last argument from previous command
!* # grab all arguments from previous command
^F^f # change first instance of "F" to "f" in last command (i.e., ^error^correction)

==Command movements==
''Note: The carret <code>^</code> symbols means <code>Ctrl+</code>.''
^w # erase word under cursor
^u # erase from here to beginning of the line
^a # move the cursor to the beginning of the line
^e # move the cursor to the end of the line

==Brace expansion==
Instead of doing this:
cp filename filename-old
cp filename-old filename
Try this:
cp filename{,-old}
cp filename{-old,}

*Create multiple files
touch a{1,2,3}b # creates 'a1b', 'a2b', and 'a3b'
touch {f1,f2,f3,}o # creates 'f1o', 'f2o', 'f3o', and 'o'

*List all files '<code>/usr/bin/foo</code>', '<code>/usr/sbin/foo</code>', '<code>/usr/local/bin/foo</code>', and '<code>/usr/local/sbin/foo</code>':
ls /usr/{,local/}{,s}bin/foo

==Word modifiers==
h # remove a trailing file name component, leaving only the head.
t # remove all leading file name components, leaving the tail.
r # remove a trailing suffix of the form .xxx, leaving the basename.
e # remove all but the trailing suffix.

*First list a file, then cd into its directory
ls -l foo/bar.txt
cd !$:h # changes pwd to 'foo'

*Create a file and a directory as the basename of the file
touch foo.txt
mkdir !$:r # creates a directory called 'foo' (without the .txt)

*Stacked word modifiers: Download a file to <code>/tmp</code>, and then create a directory for the contents of that tar file in <code>/usr/local/src</code>. Then extract the contents of the tarball into the newly created directory:
cd /tmp
wget <nowiki>http://www.example.com/path/SomePackageName.tar.gz</nowiki>
cd /usr/local/src/
mkdir !-2$:t:r:r # creates a directory called 'SomePackageName'
cd !$ # enter the above directory
tar xvzf /tmp/!-4$:t # extract the contents of 'SomePackageName.tar.gz' here

*Substitution:
ls Foo # file/directory does not exist, so:
!!:s/Foo/foo/ # change 'Foo' to 'foo' in last command

*Substitution (global):
ls Foo1; ls Foo2 # neither file/directory exist, so:
!!:gs/F/f/ # replace all 'F' with 'f' in previous command

@@ Line 123: / Line 123: @@
   $ ssh user@remotehost 'bash -s' < script.sh
   $ ssh user@remotehost 'bash -s' <<'EOS'
-  # The following commands run on the remote host
+ # The following commands will be run on the remote host
-  pwd
+ pwd
-  touch foobar
+ touch foobar
-  uptime
+ uptime
-  EOS
+ EOS
 The <code>bash -s</code> command means: execute the following commands in a new bash session. The <code>-s</code> flag makes it read from standard input.

← Older revision		Revision as of 22:37, 21 September 2021
Line 118:		Line 118:
	fi		fi
	};		};
		+
		+	==Run a local script on a remote host==
		+
		+	$ ssh user@remotehost 'bash -s' < script.sh
		+	$ ssh user@remotehost 'bash -s' <<'EOS'
		+	# The following commands run on the remote host
		+	pwd
		+	touch foobar
		+	uptime
		+	EOS
		+
		+	The <code>bash -s</code> command means: execute the following commands in a new bash session. The <code>-s</code> flag makes it read from standard input.

@@ Line 45: / Line 45: @@
   mkdir /usr/local/src/bash/{old,new,dist,bugs}
   chown root /usr/{ucb/{ex,edit},lib/{ex?.?*,how_ex}}
 ==Word modifiers==

@@ Line 35: / Line 35: @@
 *Sequences
-  $ echo {1..3}{foo,bar}
+  echo {1..3}{foo,bar}  # prints '1foo 1bar 2foo 2bar 3foo 3bar'
 foo 1bar 2foo 2bar 3foo 3bar
 *Make a backup (not super useful, but nifty)
-  cp my.cnf{,.bak}
+  cp my.cnf{,.bak}  # i.e., 'cp my.cnf my.cnf.bak'
-  # now restore the original
+  # to restore the original
-  cp my.cnf{.bak,}
+  cp my.cnf{.bak,}  # i.e., 'cp my.cnf.bak my.cnf'
 *Etc.

@@ Line 33: / Line 33: @@
 *List the files '<code>/usr/bin/foo</code>', '<code>/usr/sbin/foo</code>', '<code>/usr/local/bin/foo</code>', and '<code>/usr/local/sbin/foo</code>':
   ls /usr/{,local/}{,s}bin/foo
 *Etc.

@@ Line 31: / Line 31: @@
   touch {f1,f2,f3,}o   # creates 'f1o', 'f2o', 'f3o', and 'o'
-*List all files '<code>/usr/bin/foo</code>', '<code>/usr/sbin/foo</code>', '<code>/usr/local/bin/foo</code>', and '<code>/usr/local/sbin/foo</code>':
+*List the files '<code>/usr/bin/foo</code>', '<code>/usr/sbin/foo</code>', '<code>/usr/local/bin/foo</code>', and '<code>/usr/local/sbin/foo</code>':
   ls /usr/{,local/}{,s}bin/foo

@@ Line 1: / Line 1: @@
 ==History functions==
   history  # display history for current tty
@@ Line 31: / Line 33: @@
 *List all files '<code>/usr/bin/foo</code>', '<code>/usr/sbin/foo</code>', '<code>/usr/local/bin/foo</code>', and '<code>/usr/local/sbin/foo</code>':
   ls /usr/{,local/}{,s}bin/foo
 ==Word modifiers==
@@ Line 61: / Line 67: @@
   ls Foo1; ls Foo2  # neither file/directory exist, so:
   !!:gs/F/f/        # replace all 'F' with 'f' in previous command