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Every new command is wrapped in a tweet and posted to Twitter. Following the stream is a great way of staying abreast of the latest commands. For the more discerning, there are Twitter accounts for commands that get a minimum of 3 and 10 votes - that way only the great commands get tweeted.
Use your favourite RSS aggregator to stay in touch with the latest commands. There are feeds mirroring the 3 Twitter streams as well as for virtually every other subset (users, tags, functions,…):
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Lists directory size up to a maximum traversal depth on systems like IBM AIX, where the du command doesn't have Linux's --max-depth option. AIX's du uses -g to display directory size on gigabytes, -m to use megabytes, and -k to use kilobytes. tr### is a Perl function that replaces characters and returns the amount of changed characters, so in this case it will return how many slashes there were in the full path name.
This command allows you to mirror folders or files with rsync using a secure SSH channel with a forced HMAC integrity algorithm. Use this if you are absolutely adamant about preserving data integrity while mirroring a set of files. --partial is for resumability.
This command is used to verify a sha256sum-formatted file hash list on IBM AIX or any other UNIX-like OS that has openssl but doesn't have sha256sum by default. Steps:
1: Save to the filesystem a script that:
A: Receives as arguments the two parts of one line of a sha256sum listing
B: Feeds a file into openssl on SHA256 standard input hash calculation mode, and saves the result
C: Compares the calculated hash against the one received as argument
D: Outputs the result in a sha256sum-like format
2: Make the script runnable
3: Feed the sha256sum listing to xargs, running the aforementioned script and passing 2 arguments at a time
This command is for UNIX OSes that have plain vanilla System V UNIX commands instead of their more functional GNU counterparts, such as IBM AIX.
This command is for producing GNU sha256sum-compatible hashes on UNIX systems that don't have sha256sum but do have OpenSSL, such as stock IBM AIX.
1.- Saves a wrapper script for UNIX find that does the following:
A.- Feeds a file to openssl on SHA256 hash calculation mode
B.- Echoes the output followed by the filename
2.- Makes the file executable
3.- Runs find on a directory, only processing files, and running on each one the wrapper script that calculates SHA256 hashes
Pending is figuring out how to verify a sha256sum file on a similar environment.