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There are some environments that use this value for password and account expiration. It's helpful to be able to quickly determine the number of days since the Unix epoch (dse) when working directly with the configuration files as an administrator.
Nobody wants the boss to notice when you're slacking off. This will fill your shell with random data, parts of it highlighted. Note that 'highlight' is the Perl module App::highlight, not "a universal sourcecode to formatted text converter." You'll also need Term::ANSIColor.
The above one-liner could be run against all HTML files in a directory. It renames the HTML files based on the text contained in their title tag. This helped me in a situation where I had a directory containing thousands of HTML documents with meaningless filenames.
F filters using first word. $F - 2nd, and so on.
Not really better - just different ;)
There's probably a really simple solution out there somewhere...
If you are in an environment where you don't have the base64 executable or MIME tools available, this can be very handy for salvaging email attachments when the headers are mangled but the encoded document itself is intact.
Fun idea! This one adds seconds and keeps running on the same line. Perl's probably cheating though. :)
This command turns a multi-line file into a single line joined with <SOMETEXT>. To skip blank lines, use:
perl -pe '(eof()||s/^\s*$//)||s/\n/<SOMETEXT>/g' file.txt
I used this to mass install a lot of perl stuff. Threw it together because I was feeling *especially* lazy. The 'perl' and the 'module' can be replaced with whatever you like.
In this way it doesn't have problems with filenames with spaces.
Today I needed a way to print various character classes to use as input for a program I was writing. Also a nice way to visualize character classes.
Safe for whitespaces in names.
Parse the output of git status.
Once the line '# Changed but not updated:' has passed print every last part of the line if it exists on disk.
**NOTE** Tekhne's alternative is much more succinct and its output conforms to the files actual contents rather than with white space removed
My command on the other hand uses bash process substitution (and "Minimal" Perl), instead of files, to first remove leading and trailing white space from lines, before diff'ing the streams. Very useful when differences in indentation, such as in programming source code files, may be irrelevant
This deals nicely with filenames containing special characters and can deal with more files than can fit on a commandline. It also avoids spawning du.
Perl variant of echo several blank lines command
Function: char * crypt (const char *key, const char *salt)
The crypt function takes a password, key, as a string, and a salt character array which is described below, and returns a printable ASCII string which starts with another salt. It is believed that, given the output of the function, the best way to find a key that will produce that output is to guess values of key until the original value of key is found.
The salt parameter does two things. Firstly, it selects which algorithm is used, the MD5-based one or the DES-based one. Secondly, it makes life harder for someone trying to guess passwords against a file containing many passwords; without a salt, an intruder can make a guess, run crypt on it once, and compare the result with all the passwords. With a salt, the intruder must run crypt once for each different salt.
For the MD5-based algorithm, the salt should consist of the string $1$, followed by up to 8 characters, terminated by either another $ or the end of the string. The result of crypt will be the salt, followed by a $ if the salt didn't end with one, followed by 22 characters from the alphabet ./0-9A-Za-z, up to 34 characters total. Every character in the key is significant.
For the DES-based algorithm, the salt should consist of two characters from the alphabet ./0-9A-Za-z, and the result of crypt will be those two characters followed by 11 more from the same alphabet, 13 in total. Only the first 8 characters in the key are significant.
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