Using $_ in the chmod command saved a good bit of typing ? obviously the $_ will contain the path to the file we?re talking about, as it was the last argument to the previous command. source: http://www.preshweb.co.uk/2007/07/bashs-_-variable-last-argument/ Show Sample Output
An example of this command that includes the -name arg. Show Sample Output
Allows to change 'shell' compatible files execution bit even if their name is not *.sh
Linux users wanting to extract text from PDF files in the current directory and its sub-directories can use this command. It requires "bash", "ps2ascii" and "par", and the PARINIT environment variable sanely set (see man par). WARNING: the file "junk.sh" will be created, run, and destroyed in the current directory, so you _must_ have sufficient rights. Edit the command if you need to avoid using the file name "junk.sh"
`pwd` returns the current path `grep -o` prints each slash on new line perl generates the paths sequence: './.', './../.', ... `readlink` canonicalizes paths (it makes the things more transparent) `xargs -tn1` applies chmod for each of them. Each command applied is getting printed to STDERR. Show Sample Output
example of using zsh extended globbing
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. Show Sample Output
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 Show Sample Output
One liner that basically duplicates ssh-copy-id functionality by taking care of most common issues of SSH password-less ssh logins: - missing key on the remote server - braindead permissions *cough* RHEL *cough* Show Sample Output
Permission modes are noted as following: 7 read, write and execute rwx 6 read and write rw- 5 read and execute r-x 4 read only r-- 3 write and execute -wx 2 write only -w- 1 execute only --x 0 none --- The 'execute' permission when set on a directory means 'allow entering directory' https://en.wikipedia.org/wiki/Modes_%28Unix%29 https://en.wikipedia.org/wiki/Chmod http://www.tutorialspoint.com/unix/unix-file-permission.htm
This is equivalent to $chmod 754 /path/to/file The 3 first symbol represent permissions for the file's owner (read/write/execute). Symbols 4-5-6 represent permissions for the file's group (read/write) Symboles 7-8-9 represent permissions for other users (read-only) Owner permissions can be altered with $chmod u+rw (give r/w permissions) Group permissions can be altered with $chmod g-w (remove write permission) Other users' permissions can be altered with $chmod o-rwx (remove r/w/execute permissions) Permissions for ALL can be altered with $chmod a+rwx (give everyone full permissions)
This command would find the file secret.txt and change its permissions to 755.
executes from your current directory down
forces user to rw, group to r, and other to no access. files will not be marked executable. directories will be executable for users and groups only. Show Sample Output
Mac install ssh-copy-id
From there on out, you would upload keys to a server like this:
(make sure to double quote the full path to your key)
ssh-copy-id -i "/PATH/TO/YOUR/PRIVATE/KEY" username@server
or, if your SSH server uses a different port (often, they will require that the port be '2222' or some other nonsense:
(note the double quotes on *both* the "/path/to/key" and "user@server -pXXXX"):
ssh-copy-id -i "/PATH/TO/YOUR/PRIVATE/KEY" "username@server -pXXXX"
...where XXXX is the ssh port on that server
xargs is a more elegant approach to executing a command on find results then -exec as -exec is meant as a filtering flag.
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