Commands using cat (514)

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Colorized grep in less
Get your colorized grep output in less(1). This involves two things: forcing grep to output colors even though it's not going to a terminal and telling less to handle those properly.

Pipe a textfile to vim and move the cursor to a certain line
This command is more for demonstrating piping to vim and jumping to a specific line than anything else. Exit vim with :q! +23 jumps to line 23 - make vim receive the data from the pipe

Get last sleep time on a Mac
Similarly for last wake time: $ sysctl -a | grep waketime

Print a list of all hardlinks in the working directory, recursively
libpurple likes to hardlink files repeatedly. To ignore libpurple, use sed: | sed '/\.\/\.purple/d'

list files recursively by size

Display a block of text with AWK
I find this terribly useful for grepping through a file, looking for just a block of text. There's "grep -A # pattern file.txt" to see a specific number of lines following your pattern, but what if you want to see the whole block? Say, the output of "dmidecode" (as root): $ dmidecode | awk '/Battery/,/^$/' Will show me everything following the battery block up to the next block of text. Again, I find this extremely useful when I want to see whole blocks of text based on a pattern, and I don't care to see the rest of the data in output. This could be used against the '/etc/securetty/user' file on Unix to find the block of a specific user. It could be used against VirtualHosts or Directories on Apache to find specific definitions. The scenarios go on for any text formatted in a block fashion. Very handy.

Move all files between to date
In a folder with many files and folders, you want to move all files where the date is >= the file olderFilesNameToMove and

Convert seconds to [DD:][HH:]MM:SS
Converts any number of seconds into days, hours, minutes and seconds. sec2dhms() { declare -i SS="$1" D=$(( SS / 86400 )) H=$(( SS % 86400 / 3600 )) M=$(( SS % 3600 / 60 )) S=$(( SS % 60 )) [ "$D" -gt 0 ] && echo -n "${D}:" [ "$H" -gt 0 ] && printf "%02g:" "$H" printf "%02g:%02g\n" "$M" "$S" }

This is N5 sorta like rot13 but with numbers only
This is N5 sorta like rot13 but with numbers only. Encrypt echo "$1" | xxd -p | tr '0-9' '5-90-6' Decrypt echo "$1" | tr '0-9' '5-90-6' | xxd -r -p

Replaces a color in a PDF document, useful for removing a dark background before printing.
The pdf is first converted to a bitmap, so change "-density" to match your printer resolution. Also be careful about the RAM required. In this example rgb(0,0,0) is replaced by rgb(255,255,255), change to suit your needs.


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