Commands by arld101 (1)

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Compare a remote file with a local file
Useful for checking if there are differences between local and remote files.

list all files in a directory, sorted in reverse order by modification time, use file descriptors.
It's both silly, and infinitely useful. Especially useful in logfile directories where you want to know what file is being updated while troubleshooting.

Colorize matching string without skipping others
this is useful to highlight only some code without losing other lines (eg. software, logs, scripts)

easily strace all your apache processes
This one-liner will use strace to attach to all of the currently running apache processes output and piped from the initial "ps auxw" command into some awk.

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" }

In Mac OS X, read the copy area (CMD + V) and convert text to audible speech

Set file access control lists
The file myfile is owned by tom and has read and write permissions for tom. Group and other permissions are empty which make myfile readable and writable only by tom. setfacl enables user tom to give read permission to user john only. The command 'ls -l' shows a '+' sign telling us that file access control list has been setup for myfile.

Convert CSV to JSON
Replace 'csv_file.csv' with your filename.

Find the package that installed a command

Copy files to a remote host with SFTP with a leading dot, then rename them to the real file name
Usage: $ sftp-cp * | sftp [email protected]:/dir This is useful if there is a process on the remote machine waiting for files in an incoming directory. This way it won't see half-transmitted files if it ignores hidden files.


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