13
votes
3answers
2k views

Why isn't there any shell command to create files?

Attention please: I am not asking how to make a file from the command line! I have been using touch for making files for years without paying attention that its main purpose is something else. If ...
2
votes
1answer
51 views

Difference between “eval” and “source /dev/stdin”

What is the difference between eval and source /dev/stdin? For example, we can run a list of commands in various ways like this. with eval. comd="ls" eval "$comd" with source /dev/stdin printf ...
3
votes
1answer
28 views

Change script to use whiptail instead of zenity

I'm having difficulty converting some zenity based script to use whiptail instead. The working script looks something like this: #!/bin/bash xfreerdp /v:farm.company.com \ /d:company.com \ ...
3
votes
1answer
40 views

setting output of a command to a variable [duplicate]

How can I put the output of head -15 textfile.txt to a variable $X to use it in an if command like this: if $X = 'disabled' then ?
4
votes
1answer
54 views

One liner for padding columns (similar to printf) of output from the previous pipe command?

I'd normally use printf to pad each cell with enough whitespace to maintain header position over its respective column. I'm wondering now, whether there's a way to do this on one line. I'm currently ...
0
votes
0answers
27 views

What do the number in the file metadata mean [duplicate]

I typed ls -l in the terminal to get the file metadata of all files in the current folder What do the circled number : 1 & 2 represent in regard to the file metadata ???
3
votes
1answer
97 views

bash command line editing (Emacs shortcuts)

When writing a command on the bash command line, I can use CTRL+w to delete a word backwards, or ALT+d to delete word forwards. The problem is, that these two shortcuts are not exactly complementary: ...
1
vote
1answer
74 views

Pass bash script arguments in double quotes to php cli script

I am trying to pass arguments to a bash script and then to a php script, I have literally looked at 30+ links, and tried over a dozen examples, and I for whatever reason have not been able to get the ...
2
votes
3answers
54 views

Tar compress folder without specifying the filename

Is it possible to use tar to compress a folder without giving the filename of the archive to store in? Normally you use: tar -zcvf prog-1-jan-2005.tar.gz /home/jerry/prog I want to do something ...
4
votes
3answers
65 views

Why does export -p exclude $_ variable?

As far I know, there are 3 ways to see exported variables: $ export -p | wc -l 50 $ env | wc -l 51 $ printenv | wc -l 51 As you can see, export -p misses single variable. It's a $_ one: $ diff ...
20
votes
2answers
529 views

How do I move all files output from a command?

I have this grep command to find files without the word Attachments in them. grep -L -- Attachments * I want to move all the files that are output from that command. How do I do that in bash? Do I ...
2
votes
2answers
50 views

What is the bash syntax for extracting the values from multiple instances of the same argument?

I want to use multiple instances of command line paramater such as the -d option used by PHP for passing PHP options. I am currently using the getopts command in bash. With PHP invocation it would ...
2
votes
2answers
91 views

Command Line Photo Organiser Like Shotwell but to run on headless server

Does anyone know of a program (or even bash script) that can take photos from various folders and then consolidate them into one place and organise them into a directory structure by date in the way ...
3
votes
1answer
27 views

Script to dripfeed files

I need to write a script that will check a directory for a given file type, say *.mov, and move up to, say, 50GB worth into another directory. The purpose being that we have a huge bunch of files that ...
17
votes
2answers
598 views

^x^y unix trick for all instances in last command?

One of my favorite Unix tricks is ^x^y, which will take the last command and replace the first instance of "x" with "y". However, I'm wondering if a similar trick works to replace all instances of "x" ...
2
votes
1answer
67 views

Copy files based on date/time from subset of directories

I'm teaching a class where (~80) students are submitting assignments that I can access via webdav, organized by student in directories named by their unique identifier. The students are split into ...
4
votes
2answers
133 views

Dump process's stdin and stdout

I have two processes, let's say Parent and Child. Parent launches the Child and communicates with it through child's stdin and stdout. Parent <-> Child These processes use text protocol and I ...
0
votes
0answers
101 views

change the panel font color of the numix theme

So I loved numix and I installed it in lubuntu 13.10 and now, when I apply it, it does into show the name of the minimized app. it does not even have option to edit.
3
votes
2answers
72 views

Repeated commands in a bash pipeline

Sometimes commands repeat in pipeline command. For example (just to illustrate): $ grep -lF 'pattern' ./foo/**/*.bar | xargs dirname | xargs dirname Is there a way to shorten chaining command? For ...
2
votes
2answers
132 views

How do I share stdout between multiple processes?

I want to receive live TCP stream, and make it readable by another processes at the same time, without saving it. For example, 111.222.233.244:1234 streams actual time. Server supports only one ...
6
votes
5answers
741 views

How does one find out how many bits a file has in one command?

I know I can use ls -lat to find out how many bytes has a file and then multiply by 8 to find out how many bits. But is this possible in only one command line?
1
vote
4answers
113 views

How to start line with command from output of another command

Sometimes the output of some command include other commands. And I'd like to start that command from output without using a mouse. For example, when command is not installed there is a message with ...
2
votes
3answers
51 views

How to start first command from the list printed by command 'history | grep something'

For example, I have the following output from command: loom@loom:$ history | grep MAKE 219 ../build.sh -DCMAKE_BUILD_TYPE=Debug .. 909 history | grep MAKE How to write a command, that start ...
1
vote
2answers
63 views

How to asynchronously launch external program from cli and discard its output?

I'm writing a simple desktop initiation script which waits for disk idle, and then launches next external program (like Firefox, Skype or conky) using &, like: ps cax | grep conky > /dev/null ...
1
vote
1answer
86 views

fg a bg process because you forgot to redirect output to /dev/null

I did Ctrl+Z bg with the intention of disowning next, but I forgot to redirect, now I cant get to my terminal because the scrolling of the output (tarballed a huge directory with verbose set). How do ...
1
vote
1answer
75 views

What's the practical difference between `command` and $(command)? [duplicate]

Both give the output of the command, so what is the semantic difference between the two? Some reading led me to suspect is that $(command) is Bash syntax, and the back quotes are integrated into Unix ...
3
votes
1answer
119 views

How does the piping in this command ultimately achieve to kill the process?

I have seen the following line in a bash script for killing a process(in this case started with the command loadgen): ps xww | grep -i "loadgen" | grep "PATTERNMATCH_FACT.xml" | cut -c1-5 | xargs -i ...
4
votes
2answers
62 views

Using newline delimited list as parameter

There have been several situations where I have had some output such as thing1 thing2 thing3 But have wanted to do something like: *command* thing1 *command* thing2 *command* thing3 An example ...
1
vote
2answers
70 views

Removing “[crap-like-this]” from strings using bash parameter expansion?

If I have the following $STRING aaa.bbb.ccc.[ddd].eee.fff.[ggg].hhh is there any way, using bash parameter expansion, to echo the following aaa.bbb..ccc.eee.fff..hhh That is, remove all ...
2
votes
1answer
55 views

bash: color matching string [duplicate]

I am looking for a command which would color a matching string in text. I.e. I am looking for functionality similar to what grep does, but I want to see the complete text not only the matching lines ...
2
votes
1answer
101 views

How do I create a dialog with multiple text fields using zenity?

I want to crate a GUI for some command line programs and I need to get info from multiple text fields e.g. 'Username', 'Password' and a checkbox 'Sign automatically?'. I need to set particular ...
2
votes
1answer
113 views

Navigating the CLI: Go back N words

I'm a Vim user, so I'm learning Emacs commands for use in the Bash CLI. I know that on my systems I can use Vim-keybindings in Bash but I'd like to learn how to use it effectively in its default ...
3
votes
2answers
101 views

What is “Exit 2” from finished background job status?

I have an exercise to put in a file some data (*conf from some directories) and need to do this in background. I did it and I am wondering what is the meaning of output messages: [A@localhost tests]$ ...
1
vote
2answers
77 views

Using globbing/wildcards when Opening Files from Terminal

I have a folder A. Inside the folder, there are some files a,b,c,d and there is a subfolder, B, containing files e,f,g. Suppose I want to open files a,b,c,d: then I just type xdg-open *. However, ...
1
vote
3answers
76 views

Generate File of a certain size?

I'd like to generate a file with the name example.file. I could use touch example.file but I want the file to be exactly 24MB in size. I already checked the manpage of touch, but there is no ...
1
vote
4answers
144 views

Is there a difference between ./script and bash script?

Given a shell script file that begins as #!/bin/bash # (bash script here), and has been chmod +xed, is there any difference in running ./script and bash script from the command-line?
0
votes
1answer
300 views

Script for running sequential job

I started recently to learn using Linux. I want to write a script in bash shell to run a serial job on a cluster. I have been searching for hints and instructions on how to write such a script. I ...
0
votes
2answers
77 views

Using Pipeline to Direct Files to Program that Opens Them

I have a Music folder, in which I have some music tracks, which aren't organized too well. Thus, if I want to find a particular track, I usually type: ls Music | grep <keyword>, where ...
1
vote
2answers
105 views

How to use `ls` to group and show only a first word of directory name?

I want to define a new ls command to do something like this The first when i use ordinary ls command: $ls undergrade.AI undergrade.KDD undergrade.AI2 undergrade.micro ...
3
votes
2answers
379 views

Why does Bash history not record this command?

The command printf "#!/bin/bash\n" > t generates an error(bash: !/bin/bash\n": event not found), but hitting the up key does not recall the command so that I can modify it. Why is that? (What I ...
1
vote
2answers
243 views

Need to copy files to existing directory and remove files already there with the same name but different extension

EDIT: Total rewrite of question for clarity. I have a directory tree (new) with a bunch of files of with an extension of .new. I have an identical tree (old) where many of the files have names ...
0
votes
1answer
82 views

Am I running Bash?

I am using OS X 10.8.5. I am trying to figure out if the terminal is running bash. When I type in the following it says "getent" command not found -- but the error message seems to be coming from ...
0
votes
1answer
148 views

What command will generate average lines per minute?

I'd like to know how many average lines are written to a file per minute. Could someone help me with a command or code to generate this number?
0
votes
0answers
27 views

How to use grep command to find the matching pattern and some more characters? [duplicate]

I have a compressed JS code and I want to find a pattern, but since the file is compresses, it has only a line, and the match pattern is all the file. The output is too much large. grep -r ...
1
vote
4answers
501 views

How exactly do I create a sed script and use it to edit a file? [duplicate]

I know how to edit a file using sed one step at a time, but how would I create an actual sed script and then use it on the file to do the same things that the individual sed commands would do? For ...
1
vote
2answers
78 views

How would I use sed to detect a certain amount of numbers before it inserts a character? ###-###-####

I need to format phone numbers in a text file. They appear as (example) 8014516912 How would I format it so that I can insert a - after the first 3 numbers, and then another - after another 3 ...
1
vote
1answer
220 views

Script to delete text files

I was trying to make a script that searches for all ASCII text files in the directory that you give and after that writes path of every file to a text file. After that it suppose to show head of each ...
0
votes
1answer
266 views

How can I get my sed command to make permanent changes to a file?

Is this possible? I read somewhere that the following command would do it: sed -e [command] [file] but it appeared to do the same thing as just sed [command] [file] (it did not save the ...
2
votes
3answers
1k views

How to find and count how many files contain a certain word?

I am supposed to find and display the count of the number of files that contain the word carrot (case ignored) So far this is what I have, I am just not sure how to add the wc into it to count how ...
2
votes
1answer
71 views

Any better method than this for sorting files by their creation date?

I needed to display a list of directories sorted by their creation date and I came up with this code snippet that I thought was kind of clever. Is there a more obvious way to do this that I'm missing? ...