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Sometimes commands give you too much feedback.
Perhaps 1/100th might be enough. If so, every() is for you.
$ my_verbose_command | every 100
will print every 100th line of output.
Specifically, it will print lines 100, 200, 300, etc
If you use a negative argument it will print the *first* of a block,
$ my_verbose_command | every -100
It will print lines 1, 101, 201, 301, etc
The function wraps up this useful sed snippet:
$ ... | sed -n '0~100p'
don't print anything by default
$ sed -n
starting at line 0, then every hundred lines ( ~100 ) print.
$ '0~100p'
There's also some bash magic to test if the number is negative:
we want character 0, length 1, of variable N.
$ ${N:0:1}
If it *is* negative, strip off the first character ${N:1} is character 1 onwards (second actual character).
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.
http://public-dns.info gives a list of online dns servers. you need to change the country in url (br in this url) with your country code. this command need some time to ping all IP in list.
swap out "80" for your port of interest. Can use port number or named ports e.g. "http"
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
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.