Commands by Michelle08 (0)

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split a file by a specific number of lines
Splits the file "my_file" every 500 lines. Will create files called xx01 xx02 and so on. You can change the prefix by using the -f option. Comes in handy for splitting logfiles for example. I am using it for feeding a logfile parser with smaller files instead of one big file (due to performance reasons)

Download file with multiple simultaneous connections
`aria2c` (from the aria2 project) allows. Change -s 4 to an arbitrary number of segments to control the number of concurrent connections. It is also possible to provide multiple URLs to the same content (potentially over multiple protocols) to download the file concurrently from multiple hosts.

Remove security limitations from PDF documents using ghostscript (for Windows)
#4345 also works under windows

Send an email from the terminal when job finishes
Might as well include the status code it exited with so you know right away if it failed or not.

Simple Gumblar check command

Exclude inserting a table from a sql import
Starting with a large MySQL dump file (*.sql) remove any lines that have inserts for the specified table. Sometimes one or two tables are very large and uneeded, eg. log tables. To exclude multiple tables you can get fancy with sed, or just run the command again on subsequently generated files.

Content search.
Grep will read the contents of each file in PWD and will use the REs $1 $2 ... $n to match the contents. In case of match, grep will print the appropriate file, line number and the matching line. It's just easier to write $ ff word1 word2 word3 Instead of $ grep -rinE 'word1|word2|word3' .

Wait for file to stop changing
This loop will finish if a file hasn't changed in the last 10 seconds. . It checks the file's modification timestamp against the clock. If 10 seconds have elapsed without any change to the file, then the loop ends. . This script will give a false positive if there's a 10 second delay between updates, e.g. due to network congestion . How does it work? 'date +%s' gives the current time in seconds 'stat -c %Y' gives the file's last modification time in seconds '$(( ))' is bash's way of doing maths '[ X -lt 10 ]' tests the result is Less Than 10 otherwise sleep for 1 second and repeat . Note: Clever as this script is, inotify is smarter.

Using NMAP to check if a port is open or close
Using NMAP to check to see if port 22(SSH) is open on servers and network devices.

Ask user to confirm
Returns true if user presses the key. Use it like $ Confirm "Continue" && do action

Stay in the loop…

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