Commands by Titi (2)

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Find out how old a web page is
I used to use the Firefox "View page info" feature a lot to determine how stale the web page I was looking at was. Now that I use mostly Chrome I miss that feature, so here is a command line alternative using wget. The -S says to display the server response, the --spider says to not download any files/pages, just fetch the header. The output goes to stderr, so to grep it you use 2>&1 to combine the stderr stream with stdout, the pipe that to grep for Last-Modified. You can use curl instead if you have it installed, like this: $ curl --head -s http://osswin.sourceforge.net | grep Mod

bash shortcut: !$ !^ !* !:3 !:h and !:t
When expanding, bash output the command, so don't be affraid if you type the command. Here is the details: First examples: $echo foo bar foobar barfoo First argument: $echo !$ echo barfoo barfoo (Note that typing echo foo bar foobar barfoo && echo !$, bash substitute !$ with $:1) Last argument: $echo foo bar foobar barfoo && echo !^ echo foo bar foobar barfoo && echo barfoo foo bar foobar barfoo barfoo All the arguments: $echo !* echo foo bar foobar barfoo foo bar foobar barfoo The third argument: $echo foo bar foobar barfoo && echo !:3 echo foo bar foobar barfoo && echo foobar foo bar foobar barfoo foobar You may want to add {} for large numbers: echo !:{11} for example Now with path: $echo /usr/bin/foobar /usr/bin/foobar For the head: $echo !$:h echo /usr/bin /usr/bin And the tail: $echo !$:t echo foobar foobar You also may want to try !:h and !:t or !!3-4 for the third and the fourth (so !!:* == !!:1-$)

list files recursively by size

Picture Renamer

Which processes are listening on a specific port (e.g. port 80)
swap out "80" for your port of interest. Can use port number or named ports e.g. "http"

Get AWS temporary credentials ready to export based on a MFA virtual appliance
You might want to secure your AWS operations requiring to use a MFA token. But then to use API or tools, you need to pass credentials generated with a MFA token. This commands asks you for the MFA code and retrieves these credentials using AWS Cli. To print the exports, you can use: `awk '{ print "export AWS_ACCESS_KEY_ID=\"" $1 "\"\n" "export AWS_SECRET_ACCESS_KEY=\"" $2 "\"\n" "export AWS_SESSION_TOKEN=\"" $3 "\"" }'` You must adapt the command line to include: * $MFA_IDis ARN of the virtual MFA or serial number of the physical one * TTL for the credentials

List all execs in $PATH, usefull for grepping the resulting list
While it seems (to me at least) a little counter-intuitive to filter on name first, this requires less work for find, as it allows it to immediately discount any files that do not match the name directly from the directory listing on disk. Querying against file attributes requires reading the file attributes, which is performed for all files matching any name based predicates.

run command on a group of nodes in parallel

Erase a word
hit BACKSPACE more than once to delete more words

Join lines
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//g' file.txt


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