Last Updated: Oct. 11, 2014
Convert an Apple DMG to the more usage IMG format (Windows/Linux)
dmg2img source.dmg destination.img
Suppress overwrite prompt when copying (Linux) (note the backslash prefix)
\cp -r source/* ./
Mount a Virtualbox Shared folder:
mount -t vboxsf share_name /mount/point
Append a line to a file, without using redirection
echo "line of text to add" | tee -a /path/to/file
Get the number and count of unique IPs in a web server log file
awk '{!a[$1]++}END{for(i in a) if ( a[i] >10 ) print a[i],i }' access.log
Get the total size of files (in the current folder) modified in the last day
find . -mtime -1 -ls | awk '{total += $7} END {print total}'
Perform an inline replacement of text in all matching files
find . -type f -name "*.ext" -print | xargs sed -i 's/match/replacement/g'
find . -type f -name "*.ext" -exec sed -i 's/match/replacement/g' {} \;
Access a VirtualHost by IP:
curl --header "Host: example.com" 127.0.0.1:port
Purge a Varnish (3.x) cache entry from localhost (note: you can omit the --head
parameter and use the full URL instead of passing the Host
header; and it does work without --http1.0
).
curl -X PURGE --http1.0 --head --header "Host: example.com" 127.0.0.1/path/to/file.ext curl --compressed -X PURGE --http1.0 --head --header "Host: example.com" 127.0.0.1/path/to/file.ext
Optimize all MySQL tables:
mysqlcheck -o -u root -p --all-databases
Find if kernel is compiled with a specific option:
grep OPTION_NAME /boot/config-$(uname -r)
Testing gzip with cURL:
curl --compressed --head http://example.com/path/to/file.ext
Run a node.js – express app in production mode with forever:
NODE_ENV=production forever start app.js
Test if user has read permissions (also works for other file permissions, and file properties):
sudo -u USER test -r /path/to/file && echo 'yes' || echo 'no'
Test if a file is newer than another file:
test FILE1 -nt FILE2 && echo 'yes' || echo 'no'
Clear the NPM cache (fixes most npm install problems):
npm cache clear
Determine the device a path is mounted on:
mountpoint -d /path/
Go to the previous directory you were in:
cd -
Logout (linux shell):
Ctrl+d
Install Redis 2.8 on Amazon Linux (from Remi):
yum install http://rpms.famillecollet.com/enterprise/remi-release-6.rpm yum --enablerepo=remi install redis
Resend mails from local mbox:
cat /var/spool/mail/test | formail -I "To: user@example.com" \ -s /usr/sbin/sendmail -t -f user@example.com