User Chris Down

739 votes

Accepted

How can I resolve a hostname to an IP address in a Bash script?

answered Sep 15, 2011 at 16:29

735 votes

Accepted

Finding the PID of the process using a specific port?

linux process ip netstat

answered Dec 25, 2013 at 5:27

456 votes

Accepted

Execute vs Read bit. How do directory permissions in Linux work?

linux permissions directory

answered Sep 22, 2011 at 12:33

266 votes

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How do I determine the number of RAM slots in use?

linux command-line memory hardware

answered Mar 2, 2012 at 16:54

266 votes

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How to rsync only new files

rsync

answered Mar 11, 2013 at 7:44

237 votes

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How to check if a shell is login/interactive/batch

shell

answered Dec 13, 2011 at 23:19

214 votes

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What does env x='() { :;}; command' bash do and why is it insecure?

bash shellshock vulnerability

answered Sep 24, 2014 at 20:10

199 votes

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In CentOS, what is the difference between yum update and yum upgrade?

centos yum upgrade

answered Nov 15, 2012 at 0:23

198 votes

How to use wildcards (*) when copying with scp?

wildcards scp putty

answered Dec 22, 2011 at 13:46

170 votes

watch command alias expansion

bash alias

answered Nov 25, 2011 at 12:41

168 votes

Prepending a timestamp to each line of output from a command

shell timestamps

answered Dec 13, 2011 at 11:49

164 votes

Why is "echo" so much faster than "touch"?

shell command echo

answered Apr 9, 2014 at 4:24

157 votes

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What is the difference between "sort -u" and "sort | uniq"?

bash sort uniq

answered May 16, 2013 at 11:28

140 votes

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What does the "@" (at) symbol mean on OSX ls?

permissions osx ls

answered Dec 26, 2013 at 8:06

138 votes

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Day of week {0-7} in crontab has 8 options, but we have only 7 days in a week

cron date

answered Dec 20, 2013 at 9:09

138 votes

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How do I check if a variable exists in an 'if' statement?

bash variable test

answered Jun 25, 2015 at 16:36

133 votes

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Make cd follow symbolic links

bash symlink cd-command

answered Nov 14, 2012 at 16:24

127 votes

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How to run a command that involves redirecting or piping with sudo?

shell sudo io-redirection quoting

answered Dec 26, 2013 at 13:01

120 votes

Find duplicate files

files duplicate-files

answered Apr 4, 2013 at 13:24

113 votes

Accepted

How to enable reverse search in zsh?

zsh command-history vi

answered Jan 27, 2012 at 13:54

91 votes

Can't use exclamation mark (!) in bash?

bash quoting special-characters

answered Mar 3, 2012 at 19:15

91 votes

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How do I list all installed programs?

application

answered Sep 18, 2011 at 20:26

89 votes

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In Bash scripting, what's the meaning of " $! "?

bash shell variable

answered Jul 31, 2013 at 8:56

80 votes

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What do the bash-builtins 'set' and 'export' do?

bash shell

answered Apr 4, 2013 at 9:45

80 votes

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What does the 'd' mean in ls -al results and what is that slot called?

permissions files ls

answered Dec 21, 2012 at 17:49

73 votes

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How does the Linux kernel update itself?

linux-kernel upgrade

answered Jan 21, 2020 at 13:48

70 votes

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Using sed to get rid of characters < > ,

sed

answered Feb 29, 2012 at 22:37

64 votes

How can I delete all lines in a file using vi?

vi

answered Oct 13, 2014 at 11:35

63 votes

Accepted

How can I access a directory outside a chroot from within it?

debian symlink chroot

answered Nov 14, 2012 at 15:52

61 votes

Accepted

In zsh how can I list all the environment variables?

shell zsh environment-variables

answered Feb 3, 2012 at 15:05

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768 Answers

How can I resolve a hostname to an IP address in a Bash script?

Finding the PID of the process using a specific port?

Execute vs Read bit. How do directory permissions in Linux work?

How do I determine the number of RAM slots in use?

How to rsync only new files

How to check if a shell is login/interactive/batch

What does env x='() { :;}; command' bash do and why is it insecure?

In CentOS, what is the difference between yum update and yum upgrade?

How to use wildcards (*) when copying with scp?

watch command alias expansion

Prepending a timestamp to each line of output from a command

Why is "echo" so much faster than "touch"?

What is the difference between "sort -u" and "sort | uniq"?

What does the "@" (at) symbol mean on OSX ls?

Day of week {0-7} in crontab has 8 options, but we have only 7 days in a week

How do I check if a variable exists in an 'if' statement?

Make cd follow symbolic links

How to run a command that involves redirecting or piping with sudo?

Find duplicate files

How to enable reverse search in zsh?

Can't use exclamation mark (!) in bash?

How do I list all installed programs?

In Bash scripting, what's the meaning of " $! "?

What do the bash-builtins 'set' and 'export' do?

What does the 'd' mean in ls -al results and what is that slot called?

How does the Linux kernel update itself?

Using sed to get rid of characters < > ,

How can I delete all lines in a file using vi?

How can I access a directory outside a chroot from within it?

In zsh how can I list all the environment variables?