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Chris Down's user avatar
Chris Down's user avatar
Chris Down's user avatar
Chris Down
  • Member for 12 years, 10 months
  • Last seen this week
964 votes
Accepted

Finding the PID of the process using a specific port?

829 votes
Accepted

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

499 votes
Accepted

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

319 votes
Accepted

How to rsync only new files

314 votes
Accepted

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

269 votes
Accepted

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

246 votes

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

218 votes
Accepted

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

215 votes
Accepted

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

201 votes

watch command alias expansion

195 votes

Prepending a timestamp to each line of output from a command

167 votes
Accepted

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

167 votes
Accepted

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

164 votes

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

153 votes
Accepted

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

152 votes
Accepted

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

147 votes
Accepted

Make cd follow symbolic links

139 votes
Accepted

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

134 votes
Accepted

How to enable reverse search in zsh?

133 votes

Find duplicate files

107 votes

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

100 votes
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How do I list all installed programs?

100 votes
Accepted

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

91 votes
Accepted

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

86 votes
Accepted

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

85 votes
Accepted

In zsh how can I list all the environment variables?

79 votes

How to put a newline special character into a file using the echo command and redirection operator?

78 votes
Accepted

Using sed to get rid of characters < > ,

78 votes
Accepted

Sort all directories based on their size

73 votes
Accepted

How does the Linux kernel update itself?

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