The command-line is the interactive interface to your shell.

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1answer
70 views

How can I expand a terminal using the command line? [duplicate]

When I start the terminal in my xfce Destop environment a black winodw about a quarter of the screen size appears, if I want to expand it to full screen size I have to click on the "+"-shaped symbol ...
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2answers
26 views

Transform values in a line by first field

I was wondering if there is an easy way to do the following without writing a script. Transform 1234,"a;b;d" 2345,"e;f;g;h" to 1234,a 1234,b 1234,d 2345,e 2345,f 2345,g 2345,h
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1answer
272 views

Operate X clipboard from command line

I'd like to copy and paste to the clipboard from the command line. I've found two utilities that works with "mouse" selection: xclip and xsel. But they both ignore the clipboard that is filled with ...
21
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4answers
1k views

Is it possible to redirect the output of a command into more than one command?

As far as I know, I can use the tee command to split the standard output onto the screen and further files: command -option1 -option2 argument | tee file1 file2 file3 Is it possible to redirect ...
2
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1answer
33 views

Sandbox an account and prevent it from any system modifications

I am trying to sandbox a user account to the point where it cannot edit or view any files beyond a certain folder, namely /home/user/test. This account will be compiling and running a C++ program that ...
11
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1answer
2k views

Why does the echo command do not work with at command?

when I type: at now + 1 min at>play /usr/share/sounds/startrek.wav at>ctrl+d it works, so after one minute there is actually a sound played. but, when I type: at now + 1 min at>echo ...
0
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1answer
331 views

extract number of bytes out of a file

Is it possible to extract a few number of bytes out of a file using dd ? The file is located on a secondary drive. I apologize if this is a simple question however I'm no pro at command line.
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1answer
445 views

Replacing white-space / characters with backslashes [duplicate]

I want to convert a bunch of mkvs to mp4s with the following command: for i in $(ls *mkv); do ffmpeg -i $i -vcodec copy -acodec copy $i.mp4; done; However, the filenames have whitespaces and ...
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3answers
162 views

Why do du's subdirectory values not sum up to total?

I'm trying to use du to investigate disk usage in a directory like so: du -hd1 | sort -rh This gives me a list that starts as follows 61G . 7.9G ./A 5.1G ./B 2.7G ./.C 1.6G ./.D ...
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0answers
128 views

Check if there is no GUI

Is it possible to check if a UNIX machine (Mac / Linux) has a GUI? Basically I would like to distinguish between: UNIXes with GUI (i.e. normal Macs, Linuxs) UNIXes with no GUI (i.e. Mac server/ ...
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1answer
93 views

How to switch from input mode into command mode in ed ?

As far as I know, ed starts in command mode. Once I input i,a or c ed changes into input mode. So far it worked. Now I read that in order to switch from input mode into command mode one has to input ...
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1answer
1k views

How can I redirect output files to a specific directory/folder

Suppose I have an executable in Unix. Suppose the name of the .exe file is myExe and it takes two parameters. I did not create this executable, this is a freely available one. myExe generates 4 ...
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4answers
384 views

How does “-dc” work in “cat /dev/urandom | tr -dc ”01"?

So far I know, the /dev/urandom file is one of the special files, it's purpose is to generate random characters. When I execute cat /dev/urandom a stream of strange characters, some even Chinese ...
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2answers
201 views

Why would the prompt get overwritten?

p_ash-3.2$ cp some_file1234.html /some/loc/ation/ofthe/some_file1234.html.html_Backu Have been seeing this intermittent issue with the command-line, while typing longer lines as part of any command, ...
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1answer
109 views

use `mv` command and my file gone [closed]

i want to move myfile.tar.gz to folder My command is mkdir backup mv myfile.tar.gz /backup arrrgh, and the file gone in /backup directory not exist, try using find command not shown how to ...
3
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0answers
183 views

Convention/standard on using curly braces around options

Man page for tar in arch linux SYNOPSIS section starts with: tar {A|c|d|r|t|u|x}[GnSkUWOmpsMBiajJzZhPlRvwo] [ARG...] I perfectly understand that in this situation it means that exactly one of them ...
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1answer
91 views

cd to my folders shows me an error

I just logged out my system and logged on. And i tried to get into my folder cd /u/folder It says Too many levels of symbolic links. But it worked yesterday. What could be the reason? I found ...
0
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1answer
584 views

ssh-copy-id different port

i am trying execute ssh-copy-id in one port different than 22 (default). I researched and found the command below $ssh-copy-id -i ~/.ssh/id_rsa.pub "user@192.168.0.1 -p 22001" but, when execute the ...
10
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7answers
3k views

Is it possible to reverse a command in the bash shell?

I was wondering if there is a (simple) possibility to redo/reverse a command that was executed in the bash shell? (to make it undone) Is there something similar to the ctrl+z combination to redo any ...
3
votes
3answers
831 views

Why do we have to pass the file name twice in exec functions?

I read Advanced Programming in the UNIX Environment by Stevens, 8th chapter. I read and understand all the six of exec functions. One thing I notice is, in all the exec functions: first argument is ...
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1answer
220 views

Saving from arecord on a raspberry pi across a network to a mac

I've currently got a usb mic plugged into a Raspberry Pi B+ and am using the following code to record data: arecord --buffer-time=5000000 -D plughw:1,0 -f cd -t raw | lame -r - stream.mp3 I then ...
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4answers
2k views

How to remove duplicate characters?

If I am having a line as: Thhiisss iisss mmyyy nameeee I want to print this as: This is my name What is the unix command for this?
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1answer
71 views

Why aren't sda3 and sda4 displayed with fdsik -l?

I wanted to display all my partitions, so I entered "fdisk -l". AFAIK, the format of the device file for a scsi hard disk reads like: sd_whichharddisk_whichpartition. To my surprise, after hitting ...
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0answers
158 views

What is the meaning of the string **/* when used with grep?

I came across this picture (below), obviously it is a pun or some kind of allusion incorporating command-line expressions. Frankly speaking I do not understand anything of it except for grep -n. ...
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2answers
156 views

for loop when matching both front and back of file name

I'm trying to set up a for loop to run a process on pairs of files. The names of the files look like this 36_002_CGATGT_L001_R1_005.fastq.gz 36_002_CGATGT_L001_R2_005.fastq.gz ...
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1answer
87 views

What is the meaning of (^| )ABC( |$) as an extended REGEX ?

I came here across the command grep -E '(^| )ABC( |$)' file1 I am confused how to interpret the regular expression therein, because I know the ^ and $ character as beginning and end signifier, but in ...
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1answer
54 views

How do I control output after executing a command?

.. Script Run Complete. You have new mail in /var/spool/mail/<user-name> -bash-3.2$ I have seen the above message most the times on my prompt, probably while it's idle or as soon as script ...
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0answers
41 views

mkvmerge Backward Spliting not supported why?

I tried this:- mkvmerge -o new_file.ogg --split parts:0s-104s,+94s-208s,+8s-12s,+312s-410s,+17s-21s 500.ogg Thrown this error: "The start time must be bigger than or equal to the previous part's ...
2
votes
3answers
1k views

What is the meaning of ls -d ?

I entered the man page of ls, the entry for the -d option is as follows: -d, --directory list directory entries instead of contents, and do not derefer‐ ence ...
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1answer
144 views

tail-ing a filename that is a date [duplicate]

I am creating a logfile from kermit named the current date (which is in the format of DD MMM YYYY - which can not be changed AFAIK), and using the file name as today's date. I then have a Bash script ...
1
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1answer
216 views

Replace case-insensitive string in all folder files

I'm trying to replace a string with another in all files in dir. Trying to use this command sed 's/foo/bar/' * But it replaces foo and not fOo or Foo and others. how to find "foo" ...
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2answers
602 views

Why can't I kill the shell using the PID obtained from the $$ special variable? [duplicate]

After I have learned that the $$ special variable holds the process number of the shell, I tried too kill the shell by simply: kill , however this did not work, I also tried some variations, but them ...
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votes
7answers
232 views

What is the purpose of having two variables ($@,$*) to transmit the arguments of a command into a script? [duplicate]

I have read of the special variables used in a script $@ and $*. As far as I understand, the arguments used while executing the script are stored into two special variables, once all arguments into $@ ...
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1answer
68 views

No such directory after creating it

I'm taking a basic Unix course and right now we're learning terminal. My directions are create a directory called company and subdirectories called sales, accounting and marketing. So I did that. ...
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1answer
272 views

SIPp “hello world” message to Asterisk

How do I run diagnostics against Asterisk? Asterisk is running on tleilax; and doge is on the same network (My network topology isn't optimal). Specifically, I want to do something like: sipp ...
1
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1answer
309 views

Changing themes and hot-corner settings from command-line

I want to change the elementary tweak themes and hot-corner settings on my Elementary Luna (built on Ubuntu 12.04 "Precise") from the commandline. With what command can I do this? I know how to make ...
2
votes
1answer
239 views

Linux commands for kids [closed]

My youngest daughter (6) is fascinated with the sl and gti commands. She even learned to combine them with ; and when the time comes to teach her about return values I'll show her how sl && ...
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1answer
25 views

How to display metainformation for different kinds of time of a file ?

As far as I know each name within a path, e.g. /name1/name2/name3, is allocated to one inode. This inode is a collection of meta information for each name (file or directory). Some of these ...
-1
votes
1answer
246 views

How to install stardict from a tar.gz manually ?

I have downloaded stardict-2.0.0-pre2.tar.gz and applied the extraction on it by writing: tar xzvf stardict-2.0.0-pre2.tar.gz , thereupon a new folder was created with the following content: From ...
166
votes
9answers
281k views

How do I get the size of a directory on the command line?

I tried to obtain the size of a folder (containing folders and sub folders) by using the ls command with option l. It seems to work for files (ls -l file name), but if I try to get the size of a ...
3
votes
3answers
81 views

how to remove accidentally created '~' and '..'

I'm using wget to download some webpages and I used the -P option without knowing that it wouldn't expend .. or ~. So I found I've created them after running the program. Now the problem is, how do I ...
1
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0answers
191 views

How to display entire subject line in `mail`?

There are two messages in /var/mail/test. mail Mail version 8.1.2 01/15/2001. Type ? for help. "/var/mail/test": 2 messages 2 new >N 1 test@test Tue Feb 17 15:07 18/628 *** SECURITY ...
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votes
2answers
1k views

How to create a new partitioning table on SD card from the command line ? [closed]

I have tried to mount a SD card on Linux Mint, I have found the right device file and tried: mount -t vfat /dev/sdb /mnt/zauberportal ,but it failed and I tried some variations like different types of ...
2
votes
2answers
2k views

Using find to list all files under certain directory

I'm trying to use a single line command that will find every directory (or sub-directory) named bin and will then print a list of all the files under it, but will not also list the directory names ...
1
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3answers
2k views

Simple TCP server listening on a port but not returning SYN-ACK

I am looking for a command-line TCP server (preferably a one-liner), that will listen on a specified port and when received SYN, it will not respond with SYN-ACK as usual TCP servers do. The purpose ...
0
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2answers
146 views

Simple http server from the command line that will always cause a timeout

Regarding the question Simple command line http server I would like to know, what is the simplest method for creating a http server listening on a specified port that will always cause timeout (it ...
0
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1answer
635 views

How to find with grep lines that end in a certain string?

I know that to find a REGEX that ends in a certain string I have to write "string$". Although I tried the following variations of grep : cat foo | grep "string$", cat foo | egrep "string$", grep -E ...
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2answers
353 views

Copy files to multiple computers over LAN

Good day, I am pretty new to Unix and I need to do this simple task. I have a few files, let's name them file01, file02, file03 etc. and I need to copy each of them to one computer from a list. The ...
0
votes
1answer
442 views

What does the option -C achieve in ls output?

In the man pages it says: -C list entries by columns However, I really cannot notice any difference between the output of ls or ls -C, could someone explain this to me?
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0answers
31 views

How much arguments can I pass to command? [duplicate]

Is there any limit of arguments that could be passed to C/C++, Python, Bash etc. program? Practical usage: pass bitmap data from/to C++ to/from Python program via arguments.