Commands by wytten12

Commands by wytten12 (4)

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Delete all but the last 1000 lines of file
This is sample output - yours may be different.
-2

ex -c '1,$-1000d' -c 'wq' file

wytten12 · 2017-01-10 16:22:57 1
Join lines and separate with spaces

Read vmargs.txt, which is a text file that could either be DOS-style (\r\n) or UNIX-style (\n) line endings and join the lines with a space separator. Can this be shortened/made more elegant? Show Sample Output
This is sample output - yours may be different.
```
(line1) (line2) (line3) ...
```
1

tr -d '\r' < vmargs.txt | tr '\n' ' '

wytten12 · 2016-12-31 18:20:03 2
Reports file systems with disk usage exceeding 90% on the specified host
This is sample output - yours may be different.
0

function df_func { local dfts=$(ssh $1 "df -lP | tail -n +2 | sed 's/%//'"); echo $dfts | awk '$5 > 90 {exit 1}' > /dev/null; if [ $? == 1 ]; then echo -n "$1 "; echo $dfts | awk '$5 > 90 {printf "%s %d%%\n", $6, $5}'; fi }

wytten12 · 2016-03-30 19:57:39 0
Use emacs in place of tail -f

Monitoring a log file with 'tail -f' is handy, but for emacs users monitoring the file with emacs is even better, because you can use all your familiar key bindings for copying regions, etc.
This is sample output - yours may be different.
0

function emon { emacs "$1" --eval '(auto-revert-tail-mode)' --eval '(setq buffer-read-only t)' --eval '(goto-char (point-max))' }

wytten12 · 2012-11-21 17:24:27 0

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VMware Server print out the state of all registered Virtual Machines.

I use this command on my machines running VMware Server to print out the state of all registered Virtual machines.

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

Move items from subdirectories to current directory

Find every file and move it to current directory.

a function to find the fastest DNS server

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.

Fast command-line directory browsing

After typing cd directory [enter] ls [enter] so many times, I figured I'd try to make it into a function. I was surprised how smoothly I was able to integrate it into my work on the command line. Just use cdls as you would cd. It will automatically list the directory contents after you cd into the directory. To make the command always available, add it to your .bashrc file. Not quite monumental, but still pretty convenient.

Convert ascii string to hex

Converts the ascii text to hex from bash. Check the sample output.

Get all files of particular type (say, PDF) listed on some wegpage (say, example.com)

See man wget if you want linked files and not only those hosted on the website.

finding cr-lf files aka dos files with ^M characters

Looking for carriage returns would also identify files with legacy mac line endings. To fix both types: $ perl -i -pe 's/\r\n?/\n/g' $(find . -type f -exec fgrep -l $'\r' "{}" \;)

Extract a bash function

I often need to extract a function from a bash script and this command will do it.

Sorts and compare 2 files line by line

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