Commands using cat (514)

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Find files that are older than x days
Find files that are older than x days in the working directory and list them. This will recurse all the sub-directories inside the working directory. By changing the value for -mtime, you can adjust the time and by replacing the ls command with, say, rm, you can remove those files if you wish to.

Given process ID print its environment variables
Same as previous but compatible with BSD/IPSO

add a backup (or any other) suffix to a file
Very helpful when you've got complex filenames and needs to change just some small parts of it. Renaming a file called "i-made-a-small-typo-right-here" to "i-made-a-big-typo-right-here": $ mv -vi i-made-a-{small,big}-typo-right-here You could also copy multiple files, edit, remove, process, etc.

Batch Convert SVG to PNG (in parallel)
Convert some SVG files into PNG using ImageMagick's convert command. Run the conversions in parallel to save time. This is safer than robinro's forkbomb approach :-) xargs runs four processes at a time -P4

Get first Git commit hash
git log --format=%H | tail -1 doesn't work anymore

Convert Unix newlines to DOS newlines
The ctrl+v,ctrl+m portion represents key presses that you should do. If you do it successfully you should see a ^M character appear.

Create a tar file with the current date in the name.
Same, but count of signs is little less :) .

shows history of logins on the server
outputs a history of logins on the server (top 10, when piped to 'head'); optional flags: '-a' put the hostname at the end of the line (good for long hostnames), '-i' post the IP instead of the hostname, '-F' put the full login and logout times, rather than short times.

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"

To find the LDAP clients connected to LDAP service running on Solaris


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