Commands using grep (1,935)

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Which processes are listening on a specific port (e.g. port 80)
swap out "80" for your port of interest. Can use port number or named ports e.g. "http"

show lines that appear in both file1 and file2

Delete leading whitespace from the start of each line

Spell check the text in clipboard (paste the corrected clipboard if you like)
xclip -o > /tmp/spell.tmp # Copy clipboard contents to a temp file aspell check /tmp/spell.tmp # Run aspell on that file cat /tmp/spell.tmp | xclip # Copy the results back to the clipboard, so that you can paste the corrected text I'm not sure xclip is installed in most distributions. If not, you can install x11-apps package

'readlink' equivalent using shell commands, and following all links
This is a equivalent to the GNU ' readlink' tool, but it supports following all the links, even in different directories. An interesting alternative is this one, that gets the path of the destination file $ myreadlink() { [ ! -h "$1" ] && echo "$1" || (local link="$(expr "$(command ls -ld -- "$1")" : '.*-> \(.*\)$')"; cd $(dirname $1); myreadlink "$link" | sed "s|^\([^/].*\)\$|$(dirname $1)/\1|"); }

clear current line

Disco lights in the terminal

OpenSSL one line CSR & Key generation

Add page numbers to a PDF
Put this code in a bash script. The script expects the PDF file as its only parameter. It will add a header to the PDF containing the page numbers and output it to a file with the suffix "-header.pdf" Requires enscript, ps2pdf and pdftk.

Setting reserved blocks percentage to 1%
According to tune2fs manual, reserved blocks are designed to keep your system from failing when you run out of space. Its reserves space for privileged processes such as daemons (like syslogd, for ex.) and other root level processes; also the reserved space can prevent the filesystem from fragmenting as it fills up. By default this is 5% regardless of the size of the partition. http://www.ducea.com/2008/03/04/ext3-reserved-blocks-percentage/


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