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1
vote
1answer
809 views

How to organize files in Linux/Unix shell?

I would like to try to organize my documents, and I was told that I can do this using the linux/unix cygwin terminal. I searched for the command in google but all I ever did find was organizing the ...
0
votes
2answers
134 views

return first instance of characters from a list

Lets say I have the output of this command saved to a file. cat /dev/urandom | tr -dc '[:graph:]' | fold -w 1000 | perl -pe 's/(.)(?=.*?\1)//g' | head -n 50 I would like to compare only the first n ...
0
votes
2answers
556 views

Extracting a certain folder from a tarball - how do I tell it where to put the file once extracted?

I've looked around at multiple sources for this question and I know how to extract the file, but neither source told me how to state where to put the folder once it has been extracted. I tried this: ...
0
votes
1answer
314 views

Excluding files whilst using tar to zip site contents not working [closed]

I'm trying to zip the contents of a site using tar and exclude a bunch of folders and error_log files but it doesn't seem to be working, when it's processing I still see many of the excluded files ...
2
votes
3answers
3k views

How can I access the history buffer in sh? (not in Bash)

Is there a command history in sh, for example how to access it, and as well, how to ensure it is clear? To clarify shells here: let's say you've logged on to a non-Gui Linux system, and $SHELL is ...
1
vote
2answers
1k views

how to move all files from a pipe into a directory ?

I performed a file-command on all elements in my Desktop directory: ~/Desktop > file * then I grepped all the lines who have the string "image" in the description: ~/Desktop > file * | grep "...
0
votes
3answers
4k views

Using the tr command

Assume that the file ft has 25 lines of text. Explain the command: tail -15 ft | tr "a" "A" > ft and tell me how many lines the file ft has after the execution of the command. I understand that ...
1
vote
3answers
295 views

How shell processes the content of command line in order to execute?

How shell processes the content of command line in order to execute? Command first and then option and arguments. Dividing command line into segments. Processes from beginning to the end.
7
votes
3answers
6k views

How can I CTRL^C out of a password prompt?

Say I started a su command, and I want to cancel it. Control+C doesn't work for su like it does for sudo... I have to finish the prompt (either by getting the password wrong enough times or by ...
1
vote
2answers
4k views

How do I use a temporary environment variable in a bash for loop?

I want to run YII_ENV=prod yii kw/test ten times. I tried $ YII_ENV=prod for x in 1..10 do; yii kw/test done; -bash: for: command not found 1304682651 (Seemed to run once.) I also tried $ for x in {...
3
votes
2answers
588 views

How to copy modified files while preserving folder structure

I have made many changes to files in my PHP project and I want to push those changes to our server via FileZilla FTP. Rather than push all of the files, I would like to find only the files that have ...
0
votes
2answers
584 views

Bash syntax error when `cd`ing into directory

**So, after doing a little digging, I got it to work. You do get far enough in the install using WINE for this to work properly. Here are the steps: Open the shell, and type in cd .wine cd ...
2
votes
1answer
102 views

Comparing ping times in FreeBSD sh

How can I strip the time from a ping return? For example: 64 bytes from 10.3.0.1: icmp_seq=0 ttl=63 time=2.610 ms I want to grab the value after time= and pass it to a test like: if time>=50.0; ...
5
votes
5answers
3k views

What does pwd output?

Does the command pwd in a shell script output the directory the shell script is in?
2
votes
3answers
485 views

Can the Bash shell “Ignore” Excess copy-paste text?

Say, I have a "Quick&Dirty" Perl script in a gui text editor, and I start the Perl interpreter in a terminal window which is running Bash. I can copy-paste the Perl script to the terminal & ...
0
votes
1answer
97 views

get command line agrument by variable in shell script

I want to get the arg of a command from a var that has the index in it of the arg that I want. Something like this # command in terminal, `foo -r -f value_wanted` index="3" var=$"$index" echo $var ##...
2
votes
4answers
1k views

Moving and renaming hundreds of .jpg files, all named 5003.jpg

So here's the deal, my girlfriend wants me to transfer all of her photos off from her iPhone onto her laptop (on which we are running Ubuntu 14.04). All of the dedicated programs I tried to do this ...
15
votes
4answers
5k views

Why doesn't echo called as /bin/sh -c echo foo output anything?

For example, while this works: $ echo foo foo This doesn't: $ /bin/sh -c echo foo Whereas this does: $ /bin/sh -c 'echo foo; echo bar' foo bar Is there an explanation?
0
votes
1answer
284 views

Whatis command (shell builtin vs executable programs)

I know that whatis command is used to output a brief description about an executable program (Command). So both whatis cd whatis type Will print: nothing appropriate (Because from my ...
4
votes
2answers
1k views

The type command can't distinguish between an executable command and a shell script

So I was reading the book The Linux Command Line, and it says that commands are of four types: (1) executable programs (2) shell builtins (3) shell functions (shell scripts) (4) ...
6
votes
8answers
898 views

Generate two sequences of numbers separated by “|”

I'm using bash (CentOS 5) and looking to generate this output (I assume I could use seq or echo together maybe?): 1|1, 2|2, 3|3, .... 31|31, 32|32, 33|33, I googled seq examples for over two hours ...
4
votes
1answer
674 views

How the terminal can run programs and show its output? [closed]

I'm slowly creating a mental model of how linux works, and I've tried to simplify the most, my model of how linux works. Let's assume that the kernel boots and inits the only software it's gonna run: ...
1
vote
2answers
6k views

Remove file with pound signs around it [duplicate]

I am using SSH to another terminal with very limited disk space. upon typing ls I see a file called #korpus.txt#. I suspect this file is an emacs buffer, but upon running emacs and trying to kill it ...
21
votes
2answers
42k views

How to Count the Number of Lines of an Output?

Let say I have the program: Calculate.py Is there a unix command-line that counts the number of lines outputted from my program, Calculate.py?
2
votes
1answer
719 views

Difference between writing `function Name { …; }`, `Name () { …; }` and `function Name () { …; }` in bash [duplicate]

You can write a bash functions several ways: function JoinStrings { ...; } Or function JoinStrings () { ...; } Or JoinStrings () { ...; } Is there any difference between these ...
1
vote
1answer
86 views

How to emulate returning arbitrary values from shell functions?

Shell functions are just statements and they don't return values. Can anyone share best practice on writing functions that return values in bash? Let's say I've a function that joins two strings: ...
2
votes
4answers
557 views

Interactively add arguments line-by-line in bash

Sometimes it happens that I have a list of files or strings in the clipboard and want to paste it as an argument list in a bash shell: Example file list (only an example): createsnapshot.sh ...
6
votes
2answers
1k views

What is the best way to pipe the output of a command through a pager if (and only if) it is too long?

I'd like to be able to be able to wrap a command so that if its output doesn't fit in a terminal it will be automatically piped through a pager. Right now I'm using the following shell function (in ...
6
votes
3answers
373 views

Is “Arithmetic Expansion” the expected action on vars inside `[[` tests?

This script: a=2 [[ "$a" -eq 2 ]] && echo yes1 [[ $a -eq 2 ]] && echo yes2 [[ a -eq 2 ]] && echo yes3 [[ "a" -eq 2 ]] && echo yes4 Does not work in dash (and ...
1
vote
5answers
917 views

can't remove file with carriage returns

I have a file blahblah\r\n.txt that I want to remove but rm blahblah\r\n.txt does not work as I receive No such file or directory message. How to remove??
11
votes
2answers
6k views

How to redirect the output of a command to an already existing file without deleting its contents? [duplicate]

I am making a backup of some files and am creating a checksum file, checksums.txt, to later check the integrity of my data. However pasting each checksum manually into the file is inconvenient since ...
2
votes
1answer
1k views

Adding two columns together in CSV and outputting to new CSV file

I have a problem I have been trying to figure out: We have a stock file CSV, which contains the stock in multiple locations. The csv looks like this: stock_no,primary,secondary,tertiary,cstock,...
9
votes
3answers
3k views

Command redirection to multiple files: command >file1 >file2 [duplicate]

I have this command: cat somefile >file1 >file2 After I executed this command I can't figure out why file1 has nothing in it. It should have the output of the first file (somefile), but ...
5
votes
3answers
7k views

How to practice for command line? [closed]

I am reading The Linux Command Line: A Complete Introduction to learn about the command line. The book is great. However, there is a major problem for me: It does not have exercises/projects at the ...
3
votes
3answers
21k views

How do I delete the last n lines of an ascii file using shell commands? [duplicate]

How do I delete the last n lines of an ascii file using shell commands?
2
votes
1answer
116 views

String a command after a command that ends in & - EX: nohup > log & && rm log

So I guess there is actually two parts to this question, because I don't want the RM to go untill the nohup command has finished, but the problem is, I love to string together commands, but my nohup ...
19
votes
5answers
1k views

Commands to learn about an unfamiliar system [closed]

You log in to an unfamiliar UNIX or Linux system (as root). Which commands do you run to orient yourself and figure out what kind of system you are on? How do you figure out what type of hardware is ...
0
votes
2answers
366 views

What is the effect of a lone backtick at the end of a command line?

I accidentally typed in cd ` into terminal today and terminal didstrange things. It put a "> " signed on the next line followed by my cursor like it wanted some input. No matter what I entered ...
19
votes
2answers
3k views

What is the difference between * and *.* while copying?

What is the difference between following 2 commands? cp -rp /dir1/*.* /dir2/ cp -rp /dir1/* /dir2/
1
vote
3answers
226 views

How to undo typo `set -ovi`?

I wanted to execute set -o vi, but instead I did set -ovi. Now when I checking set -o I see extra weird options such as: $ set -o set -o ... update_terminal_cwd; and as result, update_terminal_cwd;...
1
vote
1answer
2k views

notify-send doesn't work from script but works from terminal

I am trying to run this script: test.sh #!/bin/bash BAT_LEVEL=`acpi -b |grep -Eo "[0-9]+%"|grep -Eo "[0-9]+"` CRIT=0 if [ $BAT_LEVEL -gt $...
0
votes
2answers
135 views

Remove leading 10-digit number from filenames

I have thousands of image files that have a 10-digit number appended to the beginning of the filenames. Immediately following each string of 10 numbers is an underscore. They look like this: ...
2
votes
3answers
128 views

Listed Frequency of Different Strings in a Particular Column

I need to figure it out how many times a particular string shows up in column 4. This is my data: 25 48656721 48656734 FAM132B ENSCAFT00000019683 4 0.51 X 53969937 53969950 FAM155B ...
8
votes
5answers
8k views

Why is Terminal automatically entering my command after pasting text?

This happens whether I use ctrl+shift+v or paste from the right-click menu. How do I make this behavior stop?
0
votes
3answers
159 views

print last line of !! command

so I want to be able to print helloworld using the !! command. I tried creating a text file with the text helloworld on it. Then I say cat textFileName It prints helloworld. Then I say !! and it ...
1
vote
3answers
37k views

Is there a way to undo a terminal command?

I just copied a whole directory into another one using cp ~/local/* ./ and actually wanted to type cp ~/local/srl* ./ so I'm founding myself with a lot of unnecessary files. I can suppress them ...
20
votes
2answers
9k views

What does CTRL+4 (and CTRL+\) do in bash?

I just found out by accident that CTRL + 4 closes programs reading stdin input from the command-line. This is how it looks when I type CTRL + 4 or CTRL + / into programs reading stdin $ cat ...
9
votes
2answers
31k views

How to use ln -s to create a command line shortcut?

I have an sh file that I would like to be able to open from the terminal at any time. I would like to type "studio" into the terminal, and have android studio open I recall using ln -s to do this, ...
1
vote
1answer
82 views

Why are arguments of a command altered when viewed by ps?

When I run my favorite app, why the arguments look different when viewed by ps? $ redshift -l 12.94:43.75 2>/dev/null 1>&2 & [1] 8637 $ ps -o cmd= -C redshift redshift -l 12.94 43.75 ...
2
votes
2answers
916 views

What other special characters are there?

For filenames, I know that you have to use either a double quotes or a backslash to include a space in your file name. Like mkdir "I like coffee" is the same as mkdir I\ like\ coffee Now when you ...