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

learn more… | top users | synonyms (1)

0
votes
3answers
55 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 ...
1
vote
0answers
41 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/ ...
0
votes
1answer
25 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 ...
2
votes
1answer
97 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 ...
0
votes
4answers
122 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 ...
0
votes
2answers
76 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, ...
0
votes
2answers
62 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
votes
0answers
46 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 ...
1
vote
1answer
58 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
votes
1answer
88 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
votes
7answers
2k 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
529 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 ...
0
votes
1answer
85 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 ...
9
votes
4answers
577 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?
0
votes
1answer
31 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 ...
1
vote
0answers
73 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. ...
1
vote
2answers
114 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 ...
0
votes
1answer
46 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 ...
1
vote
1answer
33 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 ...
1
vote
0answers
25 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 ...
1
vote
3answers
161 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 ...
0
votes
1answer
48 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
vote
1answer
59 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" ...
0
votes
2answers
90 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 ...
7
votes
7answers
199 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 $@ ...
1
vote
1answer
54 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. ...
0
votes
1answer
137 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
vote
1answer
123 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 ...
1
vote
1answer
145 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 && ...
1
vote
1answer
21 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
90 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 ...
11
votes
5answers
1k 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
69 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 ...
2
votes
0answers
75 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 ...
-1
votes
2answers
165 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
364 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 ...
0
votes
3answers
364 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
votes
2answers
56 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
votes
1answer
77 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 ...
1
vote
2answers
130 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
177 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?
1
vote
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.
0
votes
2answers
81 views

What regular expression in grep searches for strings of three same letters in a row?

I have a text file and I am using the grep command with a regular expression to get only the lines which contain three same successive letters, e.g.: aaa bbb ccc ddd What regular expression do I ...
12
votes
4answers
1k views

What is the meaning of IFS=$'\n' in bash scripting ?

at the beginning of a shell script program in the bash is the following line: IFS=$'\n' What is the meaning behind this collection of symbols ?
-1
votes
2answers
133 views

How do I get a list of all directories and files with absolute paths each line ?

Using ls -R / i get every file and directory listed that exists, but not in the desired format. What do I need to write on the command line in order to get a list in such a format, that every line ...
5
votes
3answers
487 views

How do I move all the files with the same name scattered through the file system into one folder?

I have a file system tree and on different locations within it are files with the same name. I tried the following command on the command line: find / -name "HAHA" -exec mv {} /home \; It only ...
6
votes
3answers
328 views

How do I use the regular pattern operator {m,n} in grep?

I have a text file, from which I need to select only those lines, which include the string "tt". So I tried this on the command line: grep "t{2}" textfile Allthough I know the textfile contains ...
0
votes
1answer
167 views

Command to to restart Pantheon files manager (elemenaryOS)?

After editing context menu entries (by editing files in /usr/share/contractor) I have to restart the file manager to see the changes. How to restart Pantheon Files with a command so that I don't have ...
1
vote
1answer
25 views

How do i start a sound file without displaying the window of the player ?

Whenever I type xdg-open filename or vlc filename, a window opens and start playing the filename. How can I achieve to play the sound file without displaying a corresponding window in the command line ...
1
vote
0answers
34 views

How can I get my Linux distribution name and version using the command line ? [duplicate]

I have Linux Mint Version 7.1 Rebecca. What do I need to write in the command line in order to find this information. I tried uname -a , but I got informations about my computer name, Kernel Version ...