Check These Out
This is how I typically grep. -R recurse into subdirectories, -n show line numbers of matches, -i ignore case, -s suppress "doesn't exist" and "can't read" messages, -I ignore binary files (technically, process them as having no matches, important for showing inverted results with -v)
I have grep aliased to "grep --color=auto" as well, but that's a matter of formatting not function.
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).
you don't have to spell out numbers, you can just use nu
Download Websites to 5 Level and browse offline!
-k -> convert-links (to browse offline)
-r -> recursive download
-l 5 -> level 5
example.
http://gentoo-install.com
:-)
sort is way slow by default. This tells sort to use a buffer equal to half of the available free memory. It also will use multiple process for the sort equal to the number of cpus on your machine (if greater than 1). For me, it is magnitudes faster.
If you put this in your bash_profile or startup file, it will be set correctly when bash is started.
$ sort -S1 --parallel=2 /dev/null && alias sortfast='sort -S$(($(sed '\''/MemF/!d;s/[^0-9]*//g'\'' /proc/meminfo)/2048)) $([ `nproc` -gt 1 ]&&echo -n --parallel=`nproc`)'
Alternative
$ echo|sort -S10M --parallel=2 &>/dev/null && alias sortfast="command sort -S$(($(sed '/MemT/!d;s/[^0-9]*//g' /proc/meminfo)/1024-200)) --parallel=$(($(command grep -c ^proc /proc/cpuinfo)*2))"
The (in)famous "FizzBuzz" programming challenge, answered in a single line of Bash code. The "|column" part at the end merely formats the output a bit, so if "column" is not installed on your machine you can simply omit that part. Without "|column", the solution only uses 75 characters.
The version below is expanded to multiple lines, with comments added.
for i in {1..100} # Use i to loop from "1" to "100", inclusive.
do ((i % 3)) && # If i is not divisible by 3...
x= || # ...blank out x (yes, "x= " does that). Otherwise,...
x=Fizz # ...set x to the string "Fizz".
((i % 5)) || # If i is not divisible by 5, skip (there's no "&&")...
x+=Buzz # ...Otherwise, append (not set) the string "Buzz" to x.
echo ${x:-$i} # Print x unless it is blanked out. Otherwise, print i.
done | column # Wrap output into columns (not part of the test).
Finds all *.p[ml]-files and runs a perl -c on them, checking whether Perl thinks they are syntactically correct
I use this to make skype blend better into my desktop :)
--disable-cleanlooks might not be nescessary to achieve the wanted effect.
=1 --> to free pagecache
=2 --> to free dentries and inodes
=3 --> to free pagecache, dentries and inodes
