One or a set of directives issued in the *nix environment to get information, change the state of something or to execute something. In other words: To gain an objective.

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1
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4answers
593 views

List all commands that a shell knows

What can I type at my shell (which happens to be bash) that will list all the commands that are recognized? Also, does this differ by shell? Or do all shells just have a "directory" of commands they ...
9
votes
2answers
3k views

What's the difference between “dir” and “ls”?

I have compared the man pages of dir and ls and they seem to be exactly the same. Both are part of GNU coreutils and "list directory contents". The only difference I've seen so far is that dir ...
0
votes
1answer
36 views

error ./c.sh: line 24: [: too many arguments in shell program

I am trying to make a shell script to print the amount of time user was logged into the system but I encountered a too many arguments error. I tried many methods from the internet but none worked. ...
15
votes
3answers
3k views

What does “rm is hashed” mean?

I'm going through http://mywiki.wooledge.org/BashGuide/CommandsAndArguments and came across this: $ type rm rm is hashed (/bin/rm) $ type cd cd is a shell builtin Just a little earlier, the guide ...
7
votes
3answers
10k views

find - exec rm vs -delete

I'm trying to understand the difference between these two commands: sudo find / -name .DS_Store -delete and sudo find / -name ".DS_Store" -exec rm {} \; I noticed that the execmethod is ...
0
votes
3answers
26 views

How to delete files from a directory based on the contents of a gzipped tar file?

Given that I: have a directory that contains over 1000 files have a gzip'ed tar file that contains a subset of those files (x.tgz) What is the single command line (if it is possible) that will ...
1
vote
2answers
25 views

How do i have my script execute one more command after a previous command returns a non-zero value before it is aborted?

I have a shell script that calls on a Perl script to do some file processing. The Perl scripts exits with either a zero or one value. I have the Unix set -e command at the beginning of my script to ...
2
votes
1answer
74 views

When i run “sudo su” i get --bash: command not found for everything

I'm not good with command lines nor servers. But I needed to configure for work a AMI of EC2 AWS with LINUX So I've installed a lot of stuff, moved a lot of stuff around and then I realized that sudo ...
1
vote
4answers
190 views

change last 10 characters of the base (not extension) of multiple files

I have many files of different lengths but the same extension and I have tried many commands to rename all of them at once. Is it possible to change only the last 10 characters of the base of all ...
1
vote
0answers
18 views

tmux select-pane -LDUR command - disable auto-cycling behavior

is it possible to disable the behavior which cause selecting a pane on opposite side of a tmux window if there is no more pane left in a direction select-pane command was originally triggered at? if ...
2
votes
1answer
68 views

How prevent users from running commands via dot slash for a directory?

Does anyone know if it is possible to restrict execution of commands via dot slash notation for a directory? The environment is bash on Linux. For example, I have a directory /usr/local/app/bin. In ...
0
votes
1answer
26 views

Unable to execute batch remote commands after pkill command

We've a scenario where I'm executing various remote commands at once like the following: ssh user@remote-ip " ps -A | grep java rm -rf /usr/share/tomcat/webapps/ROOT ls " The above set ...
5
votes
1answer
434 views

What exactly are commands? How to identify? [duplicate]

I want to know what exactly are Linux commands? & how to identify and locate them? (Say Introduce the "commands") In other words what are different kind/type/category of commands? How to identify ...
35
votes
3answers
13k views

How to stop the find command after first match?

Is there a way to force the find command to stop right after finding the first match?
1
vote
1answer
56 views

What does blkid stand for?

What does the command blkid stand for? I want a way to remember it. Also, what is it often used for?
88
votes
7answers
8k views

Why is cd not a program?

I've always wondered why cd isn't a program, but never managed to find the answer. Anyone know why this is the case?
0
votes
1answer
38 views

Creating an symbolic link in /bin automatically creates a second link in /usr/bin and the which command chooses /usr/bin

I just created an executable: ln -s /path/to/script.sh /bin/script then I check if everything succeeds and it does(/bin/script is created) but this has also created: /usr/bin/script and if I ...
0
votes
1answer
354 views

Running program on startup (Fedora 22/ 2015)

I tried really hard to avoid posting a new question for something so basic and already answered in a hundred places, but after spending two hours on this and trying every solution out there I'm ...
2
votes
2answers
135 views

How do you add a bash script to your PATH variable using symlinks?

I run a gaming server called PocketMine. So basically I have a folder in my home directory that has a bash script to run the server: ~/PocketMine/start.sh Everytime I want to run the server I either ...
0
votes
1answer
44 views

list users who are all created by current user in linux

I have set of users with root access.I want to know list of users who are all created by currently logged in user. From below structure if user1 login to system , how to list user's like ...
3
votes
3answers
51 views

Quick change directory to a similar directory structure?

In the test environment, we have a directory structure for log files that looks like this: /var/Logs/int/app-id/region-code/log/file-name.log /var/Logs/sat/app-id/region-code/log/file-name.log ...
0
votes
3answers
177 views

Can a command be executed without a shell?

I am developing a binary executable program command to execute programs and return the output into a text field. The parameters to the command involve the command itself as it would be typed on the ...
2
votes
2answers
1k views

How to permanently enable scl CentOS 6.4?

I installed a newer version of devtoolset (1.1) and was wondering how I would go about permanently setting these to be default. Right now, when I ssh into my server running CentOS, I have to run this ...
17
votes
3answers
3k views

The “yes” command

There is a yes command in unix/linux which basically infinitely prints y to the stdout. What is the point of it, and how is it useful?
0
votes
1answer
62 views

What does this ls command do? [duplicate]

what does this command do if it was executed in my current working directory that has files in it? ls 2> result I think whatever ls writes will be redirected to the result file? Is that correct and ...
10
votes
3answers
6k views

What is the purpose of -e in sed command?

I can't find any documentation about the sed -e switch, for simple replace, do I need it? e.g. sed 's/foo/bar/' VS sed -e 's/foo/bar/'
0
votes
2answers
101 views

“date -d” command fails on Docker Alpine Linux container

I built Alpine Linux in a Docker container with the following Dockerfile: FROM alpine:3.2 RUN apk add --update jq curl && rm -rf /var/cache/apk/* the build run successfully: $ docker build ...
10
votes
1answer
26k views

ifconfig command not found

I've just installed CentOS7 as a virtual machine on my mac (osx10.9.3 + virtualbox) .Running ifconfig returns command not found. Also running sudo /sbin/ifconfig returns commmand not found. I am root. ...
0
votes
1answer
33 views

What's the inverse of the X mnemonic in chmod?

Is there a way other than find … -type f -exec chmod -x {} + to remove the x bit from u, g and/or o recursively with just chmod? The X mnemonic in chmod allows one to recursively set permissions on a ...
0
votes
4answers
108 views

Remove first 2 columns from first row of a file

I am looking for a command to remove first 2 columns from the first row of a file. The delimiter for the columns is a pipe. Number of columns vary. we just need to blindly remove first 2 columns. ...
0
votes
1answer
17 views

run remote command to save debian package list

I'd like to backup the package list(dpkg) of some remote computers to a backup server: all of them running Debian. I already configured the rsa key to login remotely as root on the other computers ...
1
vote
3answers
94 views

List of files where the line count is greater than 2

Bunch of files exist in a directory. Some files have 1 line in it, some files have more number of lines. I'm trying to display filenames from a particular directory(with full path), where the ...
3
votes
2answers
135 views

Convert all non-JPG images to JPGs

What command can I use to convert all images in a folder which are not JPGs (PNG and BMP primarily) to JPG? I'd also like the conversion quality to be 100%. And I'd like the converted images to ...
0
votes
0answers
28 views

Failed to execute the iscsiadm commands

When I am using the command: iscsiadm -m discoverydb -t st -p 10.10.11.12:3260 -I be2iscsi.00:17:a4:7a:e3:34.ipv4.0 --discover -P 1 I am getting below error: scsi host1: BC_207 : MBX Cmd Failed ...
2
votes
1answer
54 views

Failed in execute of “lsscsi” command [closed]

I can't execute the "lsscsi" command in linux, I keep getting "command not found" when I try to run it. How can I solve this issue?
1
vote
2answers
1k views

What is difference between pbrun and sudo command?

What is difference between pbrun and sudo command? I have seen people executing pbrun sudo su - what this means? I know su -, it will try to switch to root user. What speciality pbrun gives to sudo ...
0
votes
0answers
45 views

How to manage any command access privileges on debian linux

I am using Debian 7, and my desktop is xfce. I want to achieve managing any command on Linux. For example, executing /usr/bin/xfce4-taskmanager command would not require sudo privileges so any user ...
4
votes
1answer
415 views

ZIP files with size limit

Is there a command to create multiple ZIP files based on file size? So that in a folder of 600 files, totalling 1 GB, the command will create 4 zips roughly equal to 250mb. There's a similar command ...
8
votes
2answers
542 views

Finding a file type assuming wrong extension

I have an image archive I keep up. Sometimes, the sites I pull them from reformat the file while keeping the extension the same, most often making PNG images into JPG's that are still named ".png". ...
1
vote
5answers
132 views

Difference between 'ls -ltr abc*' and 'find ./ -name abc*' command? [duplicate]

To search a file in a directory, I found two commands as below: ls -ltr initialfilename* find ./ -name initialfilename* Sometime, first command gives me the search result but sometime I used to ...
3
votes
3answers
64 views

When to use XPG* version of a command?

I occasionally do work on an older Solaris machine whose default version of grep is non-POSIX-compliant. This causes problems in my rc files because the default grep on the machine doesn't support ...
2
votes
1answer
48 views

External command to force ofstream to flush

I have a C++ ofstream that, for performance reasons, I don't flush from inside the code. However, occasionally I need to inspect the file contents. Is there a Linux command that will force the ...
3
votes
2answers
179 views

How to check if vim is installed?

I want to know how to check whether a command is installed. Specifically, I want to alias vi to vim on all machines where vim is a valid command. And I want to keep my *rc files generic. But some ...
0
votes
0answers
20 views

Sed replace with command output [duplicate]

I'm trying to replace text with the contents of a file and I'm getting errors. This works: cat /tmp/test | sed -e "s/__TEST__/$(cat pass)/g" But this one doesn't cat /tmp/test | sed -e ...
0
votes
3answers
61 views

What is meaning of {} + in the exec command?

I want to know the meaning of {} + in the exec command, and what is the difference between {} + and {} \;. To be exact, what is the difference between these two: find . -type f -exec chmod 775 {} + ...
0
votes
0answers
24 views

How to find last x minute internet usage

How can i find out the last X minute download bandwidth in megabyte? i want to use it within a bash script.
0
votes
0answers
13 views

What shell extension recommends packages if command is not found and how to update it? [duplicate]

I know this question might sound a little strange but i really don't know how to describe it better. On my Debian system I have a shell extension for bash that, whenever I enter an unknown command, ...
0
votes
0answers
22 views

Recover a folder just delete [duplicate]

I just delete (was my error) a folder my_folder by doing $ rm -R my_folder, how can I recover it?
0
votes
0answers
20 views

Verify par2 on different media?

Is there an easy way to point to a par2 index file in one place and have it use a different base directory for the files to verify? Here's what I'm up to: I copy a bunch of stuff to backup media. ...
13
votes
6answers
26k views

Delete 100 lines from vi editor using single command

I am using Ubuntu and trying to delete all 100 lines from vi editor but I got interview question of doing this in one command.