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If you use 'tail -f foo.txt' and it becomes temporarily moved/deleted (ie: log rolls over) then tail will not pick up on the new foo.txt and simply waits with no output. 'tail -F' allows you to follow the file by it's name, rather than a descriptor. If foo.txt disappears, tail will wait until the filename appears again and then continues tailing.
15tail -F file -
Add this to your $HOME/.bashrc file. It will only set this prompt if it is running inside screen ($WINDOW var is set) Looks like this...
ion@atomos:~[2]$Show Sample Output4[[ "$WINDOW" ]] && PS1="\u@\h:\w[$WINDOW]\$ " -
Breaks down and numbers each line and it's fields. This is really useful when you are going to parse something with awk but aren't sure exactly where to start. Show Sample Output
16awk '{print NR": "$0; for(i=1;i<=NF;++i)print "\t"i": "$i}' -
Directly attach a remote screen session (saves a useless parent bash process)
43ssh -t remote_host screen -r -
command to decrypt:
openssl enc -aes-256-cbc -d < secret.tar.enc | tar xOf course, don't forget to rm the original files ;) You may also want to look at the openssl docs for more options.5tar c folder_to_encrypt | openssl enc -aes-256-cbc -e > secret.tar.enc -
This executes faster than
cygstart.exeI put this in a script and added it to my path:cat `which explore.sh`#!/bin/bash if [ $# -eq 0 ]; then explorer.exe $( cygpath `pwd` -w ) & else explorer.exe $( cygpath $1 -w ) & fi; Using the script you just typeexplore.sh file_or_executableNote: you can do this for any file that has an associated executable in the windows registry. This is quite handy if you want to open pictures or movies from xterm. Show Sample Output0explorer $( cygpath "/path/to/file_or_exe" -w ) -
converts any number on the 'stdin' to SI notation. My version limits to 3 digits of precious (working with 10% resistors). Show Sample Output
2$ awk '{ split(sprintf("%1.3e", $1), b, "e"); p = substr("yzafpnum_kMGTPEZY", (b[2]/3)+9, 1); o = sprintf("%f", b[1] * (10 ^ (b[2]%3))); gsub(/\./, p, o); print substr( gensub(/_[[:digit:]]*/, "", "g", o), 1, 4); }' < test.dat -
a shorter version Show Sample Output
1lynx -dump http://www.ip-adress.com/ip_tracer/?QRY=$1|sed -nr s/'^.*My IP address city: (.+)$/\1/p' -
This command finds the 5 (-n5) most frequently updated logs in /var/log, and then does a multifile tail follow of those log files. Alternately, you can do this to follow a specific list of log files: sudo tail -n0 -f /var/log/{messages,secure,cron,cups/error_log} Show Sample Output
5ls -drt /var/log/* | tail -n5 | xargs sudo tail -n0 -f -
Instead of calculating the offset and providing an offset option to mount, let lomount do the job for you by just providing the partition number you would like to loop mount.
4lomount -diskimage /path/to/your/backup.img -partition 1 /mnt/foo -
Shows a single line per interface (device), with its IPv4 settings. Shorter command, better readability in output. Show Sample Output
-3ip addr|grep "inet " -
a variation of avi4now's command - thanks by the way!
2curl -u 'username' https://api.del.icio.us/v1/posts/all | sed 's/^.*href=//g;s/>.*$//g;s/"//g' | awk '{print $1}' | grep 'http' -
to clean up the extra lines Show Sample Output
-1/sbin/ifconfig | grep inet | cut -f 2 -d ":" | cut -f 1 -d " " |egrep -v "^$" -
Same as above but slooooow it down
2while true ; do IFS="" read i; echo "$i"; sleep .01; done < <(tr -c "[:digit:]" " " < /dev/urandom | dd cbs=$COLUMNS conv=unblock | GREP_COLOR="1;32" grep --color "[^ ]") -
another way to output the IP address' of the system
-1/sbin/ifconfig | grep inet | cut -f 2 -d ":" | cut -f 1 -d " " -
1for i in `git log --all --oneline --format=%h`; do git grep SOME_STRING $i; done
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That one works on Linux. On BSD and Solaris, the ifconfig output is much easier to parse:
/sbin/ifconfig -a | awk '/inet/{print $2}'0/sbin/ifconfig | awk -F'[ :]+' '/inet addr/{print $4}' -
making lots of configurations to apache and restarting the server only to find it broken just plain sucks.
2alias restart='apache2ctl configtest && apache2ctl restart' -
-2/sbin/ifconfig eth0 | grep "inet addr" | sed -e 's/.*inet addr:\(.*\) B.*/\1/g'
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Found this useful for scripts where I needed to work with the machine's IP. If $DEVICE is not specified, this will return all IPs on the machine. If $DEVICE is set to a network adapter, it will return just that adapter's IP.
-2ifconfig $DEVICE | perl -lne '/inet addr:([\d.]+)/ and print $1' -
This is *NOT* about the -i option in grep. I guess everybody already knows that option. This is about the basic rule of life that the simplest things are sometimes the best. ;-) One day when I used "grep -i" for the umpteenth time, I decided to make this alias, and I've used it ever since, probably more often than plain grep. (In fact I also have aliases egrip and fgrip defined accordingly. I also have wrip="grep -wi" but I don't use this one that often.) If you vote this down because it's too trivial and simplistic, that's no problem. I understand that. But still this is really one of my most favourite aliases.
-2alias grip="grep -i" -
This alias finds identical lines in a file (or pipe) and prints a sorted count of them (the name "sucs" descends from the first letters of the commands). The first example shows the number of logins of users; the one who logged in most often comes last. The second example extracts web client IP addresses from a log file, then pipes the result through the "sucs" alias to find out which clients are performing the most accesses. Or pipe the first column of ps(1) output through "sucs" to see how many processes your users are running. Show Sample Output
0alias sucs="sort | uniq -c | sort -n" -
Simply shows virtualhosts enabled, root access not needed (assuming apache2ctl is non-root executable).
0/usr/sbin/apache2ctl -S -
Lists virtualhosts currently enabled for apache2, showing the ServerName:port, conf file and DocumentRoot
4/usr/sbin/apache2ctl -S 2>&1 | perl -ne 'm@.*port\s+([0-9]+)\s+\w+\s+(\S+)\s+\((.+):.*@ && do { print "$2:$1\n\t$3\n"; $root = qx{grep DocumentRoot $3}; $root =~ s/^\s+//; print "\t$root\n" };' -
-2find / | xargs ls -l | tr -s ' ' | cut -d ' ' -f 1,3,4,9
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