Commands using awk

Shell timeout variables (TMOUT) can be very liberal about what is classified as 'activity', like having an editor open. This command string will terminate the login shell for an user with more than a day's idle time.

From there, just pkg install the package you need.

Does not require input to function or complete. Number of iterations controlled by shell variable $NUM.

shows also time if its the same year or shows year if installed before actual year and also works if /etc is a link (mac os)

Have wc work on each file then add up the total with awk; get a 43% speed increase on RHEL over using "-exec cat|wc -l" and a 67% increase on my Ubuntu laptop (this is with 10MB of data in 767 files).

needs no GNU tools, as far as I see it

saves one command. Needs GNU grep though :-(

This will drop you into vim to edit all files that contain your grep string.

Show time and date when you installed your OS.

using awk

missed the last char thanks @Josay

This command uses nmap to perform reverse DNS lookups on a subnet. It produces a list of IP addresses with the corresponding PTR record for a given subnet. You can enter the subnet in CDIR notation (i.e. /24 for a Class C)). You could add "--dns-servers x.x.x.x" after the "-sL" if you need the lookups to be performed on a specific DNS server.

On some installations nmap needs sudo I believe. Also I hope awk is standard on most distros.

Only one command and not dependant on full read access to the devices.

simple way to show free swap

This command will print all fields from the given input to the end of each line, starting with the Nth field.

You can get others rates changing the "EUR/US" part. look at the url: wap.kitco.com/exrate.wml to get more options.

- convert unixtime to human-readable with awk

- useful to read logfiles with unix-timestamps, f.e. squid-log:

sudo tail -f /var/log/squid3/access.log | awk '{ print strftime("%c ", $1) $0; }

Uses the data in the /proc system, provided by the acpid, to find out the CPU temperature. Can be run on systems without lm-sensors installed as well.

This command changes all filename and directories within a directory tree to unaccented ones. I had to do this to 'sanitize' some samba-exported trees. The reason it works might seem a little difficult to see at first - it first reverses-sort by pathname length, then it renames only the basename of the path. This way it'll always go in the right order to rename everything.

Some notes:

1. You'll have to have the 'unaccent' command. On Ubuntu, just aptitude install unaccent.

2. In this case, the encoding of the tree was UTF-8 - but you might be using another one, just adjust the command to your encoding.

3. The program might spit a few harmless errors saying the files are the same - not to fear.

This create an array 'a' with wole lines. only one occurrence of each line - Not Get lines ++ !

show file withou duplicated lines

Ping sweep without NMAP