Favourite command line trick

Question

bash, bat, whatever...

What is your favourite command line hyperproductivity trick?

Answer 1

Running grep over directories with code, often with find (and sometimes xargs when needed). For me this is typically faster than using the equivalent tools in an IDE, although I guess that mostly shows my age.

Answer 2

Ctrl-R in bash to search for a previously entered command.

Answer 3

I like my bash prompt to be a different colour. In your .bashrc or .profile:

PS1='\033[01;34m\n[\u@\H \W]$\033[00m '

Answer 4

Entering

START .

to open a Windows Explorer window for the current directory.

Answer 5

Pipes in general. Imagine you want to find out how many files that have a particular string in their filename are in a folder. You could do it like this:

ls -l | grep yourstring | wc -l
# Sample output: 52

Answer 6

scripts and IF.

Answer 7

Favourite command line hyperproductivity trick:

I like the Tab key for path/file completion in bash.

---

Favourite command line tool:

man [command]

Answer 8

Piping the output of grep (or findstr) to itself to exclude things I don't want. For example:

findstr /spin /c:"foo" *.cc | findstr /v /c:".svn"

Answer 9

Turning on tab completion in a Windows command shell.

set \HKCU\Software\Microsoft\Command Processor\CompletionChar to 9

After that use tab to auto-complete filenames in shells.

I think Vista has this turned on by default but XP doesn't

Answer 10

At the Mac OS X bash prompt issuing

open Filename

starts up the application associated with Filename and loads the file.

Answer 11

I think you are looking for the Command-line Fu Website! :)

Answer 12

In tcsh, using CTRL-X+? to expand paths and aliases, CTRL-X+$ to expand variables and CTRL-X+* to expand globs.

Some examples:

> alias l less
> l
# press CTRL-X+?
> less

> set l less
> $l
# press CTRL-X+$
> less

> ls
a.c b.c c.h
> echo *.c
# press CTRL-X+*
> echo a.c b.c

Answer 13

In bash:

set -o vi

turns on vi mode. Also, adding this to ~/.inputrc will turn on vi mode for anything using readline:

set editing-mode vi
set keymap vi

I am more familiar with the vi commands than I am with the emacs ones, so these changes give me a productivity boost.

Answer 14

Insert preceding line's final parameter (bash)

Alt-. is one of the most useful key combinations; for some reason no one knows about this one. Just try it and see

Press it again and again to select older previous parameters.

Great when you want to do something else to something you used just a moment ago, try it and see.

Update Example

Let's say you have the following files in a directory:

06.Jimmies_Joys-Wolverine_Blues.flac
06.King_Oliver-Jazzin_Babies_Blues.flac
07.Cotton_Pickers-You_Tell_Her,_I_stutter.flac
07.Mammie_Smith-Lady_Luck_Blues.flac
08.Paul_Whiteman-If_I_Cant_Have_The_Sweetie.flac
08.The_Georgians-Loose_Foot.flac
09.Jelly_Roll_Morton-Wolverine_Blues.flac
09.Wades_Moulin_Rouge_Orchestra-Mobile_Blues.flac

Sadly, you didn't notice that the CDDB entry for CD6 was mislabeled CD5, and so all the entries for CD5 and CD6 are now mixed. You take out the liner notes and want to move the true CD6 music up a level and into the appropriate subdirectory because OCD compels you so. Here's what you do:

1. cd *CD5*
2. mv 06.Jtab ../*CD6*
3. mv 07.Mtab Alt-.

Using Alt-. will auto-complete ../*CD6* FTW.

Answer 15

When trying to find if a specific program is running: ps options | grep [p]rogram

That is, turning the program name into a non-self-matching regular expression.

Answer 16

Creating a m3u file from command:

dir /B *.mp3 > playlist.m3u

Answer 17

On Windows:

TaskList /M nameof.dll

Gives you a list of all the running processes that have the DLL loaded. This is useful if you're trying to track down a locking issue.

Answer 18

Here's a way to show any file in Windows Explorer (open window and highlight file; at least, if the file's directory window is not already open):

explorer /select,"c:\windows\notepad.exe"

Or, if you like "explore" (show file tree) better:

explorer /E,/select,"c:\windows\notepad.exe"

(I'm just taking notepad as an example, as that path probably exists on your PC.)

Note that Explorer will crash if the path does not exist.

Answer 19

bash-completion: the greatest things since bash completion

This gives you relevant completion suggestions for what you've currently typed. Extremely useful!

Answer 20

On Windows:

explorer /e,/root, path

Will launch an explorer instance with the root set to path. This is handy when you're browsing source code and just want an explorer view from the root of the code down.

NOTE: The strange commas are correct and there needs to be a space after the last comma and before the path.

Answer 21

I use alt-f/b in bash to jump over words along with ctrl-a/e to navigate to the end/beginning of the line. Ctrl-u deletes everything left from the cursor, ctrl-k everything right from the cursor.

On Windows you can use ctrl-left/right. Home/End, however I haven't found a shortcut to delete everything left/right from the cursor.

Answer 22

In Bash, the ! keyword thingummy.

e.g.

!ssh

runs the latest entry from your command line history that began with 'ssh'.

or

!224

reruns entry #224 from your history.

Useful when you have to run the same command several times, for example, running ssh with loads of command-line options specified.

Answer 23

From a Windows XP command prompt, might be a known feature but I use it all the time. hitting the F7 key will bring up the list of previously issued commands.

Answer 24

in bash, for loops. I particularly like the structure:

for f in *; do cd $f; for g in *; do [STUFF]; done; cd ..; done

Answer 25

in unix/sh, Using find in conjunction with while read in order to perform a common operation on certain files within a directory tree.

Change permissions of directories only:

find ./ -type d |while read x; do chmod go+rx "$x"; done

Remove files not accessed in more than a week:

find ./ -type f -atime +7| while readx; do rm "$x"; done

The find command allows one to ferret out those files with common characteristics, and the while read construct makes makes it simple to perform operations on each.

Answer 26

How to paste on windows console: alt+space+e+p

I know it's huge and complex but it saves me 50 times per day.

Answer 27

% perl -ne "print if /something/" < infile

Prints all of the lines with the regex something in them, from the file infile. "-e" tells perl to interpret the next argument as a script (&& run it), while "-n" tells perl to add a "while (<>) {}" around the whole script, which is like saying 'execute the script for every line of input'.

Great for parsing log files.

Answer 28

To cut and paste arguments to a command

cmd `cat`

paste followed by ctrl-d

Answer 29

On Windows, when working with code, often I do heavy use of Command Window Here and then findstr

findstr /c:"string_to_be_searched" /s *.cpp

Is pretty useful.

Answer 30

1. grep -v (Invert match)
2. ls -ltr (Last modified files first)
3. cat file | sed 's/old/new/' (Replace regex old with new)

Answer 31

IP range scanner

$for /L %i in (1,1,254) do @ping  192.168.1.%i -n 1 | find /i "reply" > nul
&& @echo 192.168.1.%i is alive

Answer 32

Print Disk Volumes

$fsutil fsinfo drives

would result an output like this Drives: C:\ D:\ E:\ F:\ G:\ I:\ J:\ Piping to more would result the following output $fsutil fsinfo drives | more

Drives: C:\ D:\ E:\ F:\ G:\ I:\ J:\

using for to get volumes would result an output like thi

$for /F "skip=2" %i in ('fsutil fsinfo drives ^| more') do @echo %i

D:\ E:\ F:\ G:\ I:\ J:\

then you can get first volume as follows

$for /F "tokens=2" %i in ('fsutil fsinfo drives') do @echo %i

would result an output like this C:\

any enhancement for this would be cool

Answer 33

Command line calculator to enhance batch arithmetic operations specially divison math written in C#

**class Program
    {
       static void Syntax()
        {
            System.Console.Write("Example: calc 10 + 25 or calc 10 / 2 \n");
        }

        static void Main(string[] args)
        {


            try
            {
                if (args.Length == 3 && args.Length != 0 && Microsoft.VisualBasic.Information.IsNumeric(args.GetValue(0)) && Microsoft.VisualBasic.Information.IsNumeric(args.GetValue(2)))
                {


                    //foreach (string var in args)
                    //{


                    string op = (string)args.GetValue(1);
                    double arg1 = System.Convert.ToDouble(args.GetValue(0));
                    double arg2 = System.Convert.ToDouble(args.GetValue(2));
                    switch (op)
                    {

                        case "+":


                            System.Console.Write(arg1 + arg2);

                            break;
                        case "/":
                            //double v = Convert.ToDouble(args.GetValue(2));
                            if (arg2 == 0 || arg2 == 0.0)
                                System.Console.Write("Cannot divide by zero!.");
                            else

                                System.Console.Write(arg1 / arg2);


                            break;
                        case "*":
                            System.Console.Write(arg1 * arg2);
                            break;
                        case "-":
                            System.Console.Write(arg1 - arg2);
                            break;
                        default:
                            Console.WriteLine("An attempt to an illegal operation! please check syntax.\n");
                            Syntax();
                            break;
                    }


                    //}

                }
                else
                {
                    System.Console.Write("Missing argument or bad syntax .\n");
                    Syntax();

                }
            }
            catch (Exception ex)
            {
            }

        }
    }**

then you can invoke command line compiler on it as follows %windir%\Microsoft.NET\Framework\v2.0.50727\csc.exe calc.cs

Answer 34

get count of lines with native windows tools such as

$find /v /c "no_where_string" filename

Answer 35

I have too much music I guess; so here is one thing I use that hasn't been listed:

locate -i artist | grep -i mp3$

substitute artist for song name etc. I include the "-i" options to make it case in-sensitive. I had to edit /etc/updatedb.conf to include my mounts in /media

Answer 36

to get ip settings networkid and hostid get ip address

for /f "tokens=15" %i in ('ipconfig ^| find /i "ip address"') do set ip=%i

get networkid

for /F  "tokens=1,2,3 delims=." %i in ('echo %ip%') do  @set ip=%i.%j.%k.

Answer 37

Shell-fu is a place for storing, moderating and propagating command line tips and tricks. A bit like StackOverflow, but solely for shell. You'll find plenty of answers to this question there.

Answer 38

wget -t0 -np -r -l0 "www.suckthiswebsite.com"

Answer 39

For bash, using !$ to repeat last argument to last command.

ls /var/log/messages
cp !$ !$.270809

And the magic carets, although I rarely use them nowadays:

[root@isis /] usradd -u 666 -g 10 -u guest
bash: usradd: command not found
[root@isis /] ^ra^era^
useradd -u 666 -g 10 -u guest

Last but not least, for infinite loops I use this (not a trick, just a quirk of mine :)

until [6 -eq 9]; echo "Jimi has really gotten into me."; done

Answer 40

In bash I sometimes misuse the fact that I know globbing a pattern will result in exactly two filenames. So if i have two textfiles stuff.txt and stuff.txt.org and I want to compare there contents I enter:

diff stuff.txt*

Answer 41

Copy to clipboard (in bat) :

MyCommand | clip

Actually, I just discovered it, but I'll surely use it every day now :)

Answer 42

Grep emacs from the output of ps aux, while filter out the grep emacs command itself

ps aux | grep [e]macs

Answer 43

In Bash, I like to:

• move up N directories quickly
• dynamically assign directories so that I can switch between 2-3 dirs quickly, and reference them for file copying etc

for details on the alias definitions, see my blog post. It is easy stuff but very useful.

Answer 44

!!

repeat the last command. It is useful when you type, by example:

apt-get install

and forget the sudo, so:

sudo !! 

do it for you.

Answer 45

egrep , which basically does what ps -e | grep does ^^

Answer 46

cp file.{txt, bak} to make a backup.

Answer 47

There's an excellent website for bash command line, CommandLineFu.

My favourite under linux is:

rm -rf *

Seriously though, it has to be Ctrl+A and Ctrl E for editing on the linux command line, (Home/End) respectively. There is another one that I use when messing with bootsectors...

dd if=/dev/hda3 of=/bootsect.bin bs=512 cnt=1

As for Windows, it has to be Winkey + 'R', cmd enter. Much faster than clicking on Start, Run, cmd.

Hope this helps, Best regards, Tom.

Answer 48

Using my cutomized PS1 variable:

\[\033[3;44m\]\u@\h:\W$\[\033[0m\]

Answer 49

One of my faves, in windows, is the tree command

tree <dir>

//e.g.

D:\axis2-1.2\dist>tree
Folder PATH listing
Volume serial number is 0000AC08 EC5E:85B4
D:.
+---axis2-web
¦   +---css
¦   +---Error
¦   +---images
¦   +---include
+---META-INF
+---WEB-INF
    +---classes
    +---conf
    +---lib
    +---modules
    +---services

tree /f <dir>    //lists all files too - very handy

I haven't found anything quite as nice in unix, although this comes close...

//can't remember who i got these ones from, but thanks anyway
ls -R | grep ":$" | sed -e 's/:$//' -e 's/[^-][^\/]*\//--/g' -e 's/^/   /' -e 's/-/|/'

or

find . -print | sed -e 's;[^/]*/;|____;g;s;____|; |;g'

Answer 50

Processing a file a line at a time.

cat filename | ( while read LINE ; do ... ; done )

You can also do tricks with IFS like

cat filename | ( while IFS=, read ONE TWO REST ; do ... ; done )