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

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2
votes
3answers
758 views

Convert a number of seconds elapsed to date from arbitrary start date

I want to convert a particular amount of seconds to a date. In my case the it's the number of seconds elapsed since 1st of January 0001. If it were for seconds elapsed from epoch it would be easy: $ ...
7
votes
3answers
7k views

How can I delete text before a delimiter in Linux

I need to delete text from a line before delimiter. For example: (123434): hello::{apple,orange,mango}. I need to delete text before first :. i.e. (123434). Is there any command in linux to ...
10
votes
5answers
31k views

How to pass each line of a text file as an argument to a command?

I'm looking to write a script that takes a .txt filename as an argument, reads the file line by line, and passes each line to a command. For example, it runs command --option "LINE 1", then command --...
4
votes
2answers
1k views

Change user info on the command line

I have made a user in Mint 16 but want to change its first and last name without deleting it and starting from scratch. I know how to do it with a GUI but I want to know the terminal command ...
2
votes
2answers
372 views

Less command change color of “~” and “(END)”?

How do I change the color of the "~" characters that go along the edge of a Less command output. And how to change the color "(END)" at the bottom?
0
votes
1answer
500 views

How to start a cron task?

It sounds really simple, but many times I was stuck at the beginning of learning a new command. The tutorial writer think it's natural to start, but it's not. This is the tutorial I've been reading: ...
0
votes
3answers
2k views

Mounting /dev/dvd /media on VirtualBox

I have installed Scientific Linux on VirtualBox and I am trying to follow some exercises on a book I picked up. The first thing I need to do is: mount /dev/dvd /media But when I do that, I get ...
6
votes
2answers
220 views

How many commands can be queued up with control operators?

I have been reading up on control operators, and I was wondering if there was a limit to how many commands you could line up with control operators, such as ||, && and ;. In addition, is ...
3
votes
4answers
1k views

How to disable a shell keyword?

Using enable builtin command we can disable a shell builtin command, for example echo, as follow: enable -n echo But how can we disable a shell keyword like time? If we try: enable -n time we ...
3
votes
4answers
600 views

Make many subdirectories at once

Suppose I have a directory /, and it contains many directories /mydir, /hisdir, /herdir, and each of those need to have a similar structure. For each directory in /, there needs to be a directory doc ...
2
votes
2answers
1k views

Pass a command to ROOT from a shell script and having it stay open

I am writing a bash script to perform some analysis using the program ROOT. I want to run some initial command to load the result of the analysis, then continue using ROOT interactively. The analysis ...
2
votes
2answers
363 views

Select a range of files after sorting them

One thing I notice slower for me if I switch from using a GUI file manager to CLI is: In a GUI file manager, I can quickly select a subset of files under a dir by, first sorting them according to ...
1
vote
3answers
65 views

Command to 're-apply' previous command?

Is there an easy way to re-apply a previous command to a new command line entry? Say I typed in chmod u+r,g+x file.txt but forgot the sudo. Could I simply type sudo <some easy symbol>'? ...
2
votes
1answer
240 views

Memory buffer in a bash script

I have recently finished a script that will ask for a hostname and automatically take the argument of the function and ssh into one of my work servers. Here is a copy of my script: #!/bin/bash echo ...
2
votes
2answers
210 views

Copy a folder and its content to all Nginx vhosts host

I am interested to know if a single command line that would allow me to recursively copy a folder to all of our NGINX Virtual Host htdocs folders: I need to copy that folder to all hosts located in ...
17
votes
2answers
556 views

How to retrieve lost aliases?

Let me start by saying I know this was dumb. Time and Linux make fools of us all. I made an echo command to my .bash_aliases file and erased all of my aliases, except the test alias. However, I ...
37
votes
4answers
6k views

Reverse grepping

Let's say, I have a really big text file (about 10.000.000 lines). I need to grep it from the end and save result to a file. What's the most efficient way to accomplish task?
1
vote
3answers
510 views

How to rename file using substring of the same file name [duplicate]

I want to rename my file with its substring.Because unfortunately renamed all the files in my server. Now I want to remove suffix( .gz) of all the files including files in subdirectories also. Below ...
0
votes
3answers
2k views

How do you view a sql.gz file as plain text SQL from the command line?

How do you view a sql.gz file as plain text SQL from the command line? I want to read the SQL statements stored in a .sql.gz file, from the command line on the server. I've tried tar -xzvf, but get ...
1
vote
1answer
3k views

How to have back the command prompt after calling an application [duplicate]

In terminal I just type firefox and then Firefox starts, but I can not return to command mode anymore. How can I come back to command mode? I have already tried :q or exit, but neither work.
2
votes
1answer
551 views

Formatting an external HDD with Bash script

At my workplace we have an external HDD connected to a NAS device (Synology). There is a backup tasks which runs weekly and fills the external HDD after a while. Unfortunately the Linux-based OS of ...
10
votes
2answers
5k views

Short, simple command to create a group if it doesn't already exist?

What is the cleanest way to modify this command in bash to only run if the group does not exist? groupadd somegroupname A one-liner would be best.
2
votes
1answer
135 views

Play .wav when text scrolls in terminal

After watching a TV show, I came up with a fun idea. Is there a way to take that cheesy high-pitched sound effect they play every time text scrolls down a command-line screen on TV and play it when ...
0
votes
1answer
492 views

Must pass urls in quotes

I'm trying pass a URL to mpv for it to play it as a network stream. This can be done in bash with the following syntax: $ mpv http://myvideosite.com However, zsh wants to evaluate the URL as (...
5
votes
3answers
4k views

Remove all lines in file A which contain the strings in file B

I have a CSV file users.csv with a list of userNames, userIDs, and other data: username, userid, sidebar_side, sidebar_colour "John Lennon", 90123412, "left", "blue" "Paul McCartny", 30923833, "left",...
6
votes
2answers
397 views

How to find out which program can open a given file?

Let's say I have a file thesis.pdf or picture.jpg Is there a command which returns a program to open this file with? I am aware of the command file, but it just returns the correct type of the file ...
4
votes
2answers
208 views

Use non-root user configuration for root account

When I work with the terminal and use su or sudo to execute a command with the root user's permissions, is it possible to apply the configuration of my "non-root user" (from which I am invoking su or ...
2
votes
1answer
392 views

Why are aliases missing inside of bash command?

When I run in my terminal: alias a list with all my aliases (defined in ~/bashrc and ~/.bash_aliases files) will be displayed on my terminal. That's nice and as expected! But when I run: bash -c "...
10
votes
2answers
15k views

Creating a messagebox using commandline

How can I create a message box using command-line to show a text‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌?
2
votes
0answers
81 views

How to make grub Command Line Default?

I'd like to make grub by default load it's command line instead of automatically booting from it's list of options generated by update-grub. How can I do this?
3
votes
2answers
10k views

wget to get all the files in a directory only returns index.html

I'm new to using bash, and I have been trying to wget all the files from a website to the server I have been working on. However all I'm getting back is an index.html file. I let it run for 15 minutes ...
25
votes
4answers
4k views

Is it possible to define a command in bash?

For example, can I set gb = cd /media/Dan/evolution So that everytime I execute gb in bash, I can cd to that particular directory? I find something online, alias command. But It seems can't do the ...
4
votes
6answers
35k views

How can I output the difference between 2 files?

My file consists of the the following; roughly: username:username:username:username:username The above line continues to about 600 characters. I use the awk command in order to use it as an ...
7
votes
4answers
5k views

Write text messages between Unix and Windows

Is it possible to send text messages between two users of the same LAN, but the first running Windows with cmd and the second running Linux/Unix? I am not looking for an instant messaging service. I ...
3
votes
1answer
291 views

Run command based on output of another command

OS: AIX 7100-04-1216 So basically I'm trying to write a for loop that sees which volumegroups I have on my system, which filesystems reside in those volume groups and what the size of each of those ...
2
votes
1answer
509 views

How can I make mailx inform me of new mail?

I'm trying to set up mailx on my server. On one server (Raspbian) I am informed of new mail with a message You have new mail (or something similar). On another machine (Raspbmc), I never have this ...
2
votes
2answers
113 views

How could I change Linux command to another key combination? [closed]

I'm using wmii, so Alt key Linux command was disabled. I want to change Ctrl+F and Ctrl+B to Alt+ F and Alt+ B so that I can use them to jump by word. But I searched on line, and didn't find ...
1
vote
2answers
173 views

Problem when splitting command with backslash in unix prompt

I often use the space-backslash combination ( ) to split a command and its parameters into various lines and make it more readable: /home/user> ls -ltra \ > file1.txt \ > file2.txt ...
10
votes
2answers
3k views

Check ping statistics without stopping

Is there a way to tell ping to show its usual termination statistics without stopping the execution? For instance, I'd like to quickly view: --- 8.8.8.8 ping statistics --- 2410 packets transmitted, ...
1
vote
1answer
249 views

Why does the same sed regex (after grep) fail when run in a bash script vs bash command line?

Here's the script. It is successful when I run it from the BASH prompt, but not in the script. Any ideas? When I say "fails," I mean the sed regex doesn't match anything, so there is no replaced ...
2
votes
1answer
51 views

How to install package via yum in Fedora

How do I install software using yum? Can you tell me another way to install package in Fedora?
1
vote
2answers
683 views

How to use paste command for many files whose names are not numbers? (paste columns from each file to one file)

To paste many files, whose names are incremental numbers: paste {1..8}| column -s $'\t' -t What if your files wasn't named by number, but only words? It can be up to ten files, what should I do? ...
2
votes
2answers
1k views

Configure bash and/or vim to execute source ~/.bashrc everytime I finish editing it

I would like to execute source ~/.bashrc every time I finish editing a file with vim (i.e. after :wq vim command). How should I configure vim or bash to work that way?
-1
votes
1answer
158 views

man command: is there a way to know the meaning of the output of a command >

Is there a way to know the meaning of the output of a command? Example given: If I type ls -l, I get this ouput: [root@localhost junk]# ls -l total 8 -rw-r--r-- 1 root root 1862 2012-08-25 16:20 a -...
3
votes
1answer
131 views

How to set default tabs only for cat?

I prefer to set tabs 4 however this may have some side effects, such as for example ls out put may look not properly aligned. How might I configure the terminal / cat to use four spaces for tabs for ...
1
vote
1answer
2k views

What does typing a single apostrophe do in terminal? [duplicate]

I typed in a single ' by accident and I got this as a result and exited out of it after typing ' in again. ' > > ' : command not found What does this do?
3
votes
2answers
9k views

Removing blank spaces and tabs from line without messing with line endings

I am trying to remove all spaces on a file without messing with line endings. This is to be run from inside a bash script. I have tried all the solutions here: http://stackoverflow.com/questions/...
16
votes
6answers
767 views

How to type several file names with fewer key strokes

If I want to convert a pdf to a png image with imagemagick I do something like: convert -trim -density 400 this_is_a_very_long_filename_of_my_pdf_file.pdf this_is_a_very_long_filename_of_my_pdf_file....
7
votes
2answers
319 views

Amplify quiet passages in an mp3 file

I have an mp3 file where is a dialog with two voices and one of the voices is very quiet. Is there a command or application that is able the detect the quiet passages and amplify them? The two voices ...
1
vote
3answers
662 views

Removing a directory that has no files in it

I recently created a username and a group called gamesForAdmin. Since then I deleted it and the folder I made for it is still there: drwxr-xr-x 5 root root 4096 Jul 4 11:28 . drwxr-xr-x ...