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Comment by Fizzadar | Hacker News Reader

Bash. I'm obsessed - so much so that I'll solve more complex problems taking 3x time rather than falling back to Python. And then there's bash one-liners, they're the best!

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I too love bash. It's always there. It has no dependencies. It works.

It has a dependency on the bash runtime.

And coreutils.

And often moreutils, or various others.

Often with better performance than Python or Perl

The only times I've ever had a bash script run faster than Perl or Python is when it has handed most of the work off to another utility (eg written in C).

The actual bash processing bits seem much slower than Perl or Python.

Isn't most heavy work in bash done by piping data to C based utilities, with bash just being the "glue"?

I don't think that's true with Perl at least, unless something has changed dramatically very recently.

If you use it to glue/pipe bunch of tools written in C it can easily be faster.

That's one recommend approach towards Python. E.g. numpy.

The other approach is pure Python and then using PyPy's JIT.

Which often is what you do in Bash with grep, cp, mv, find etc...

Obfuscated oneliners are where it gets really, really fun though.

I love making these, because they can be edited and iterated directly from the terminal prompt, and you can just paste them from the clipboard to see if you like them and want to keep them.

For example, the URL this oneliner spits out is actually real. The technique works almost nowhere now thanks to HTTPS (it's one of my poorest oneliners), but it's hilarious to show people who don't know about networking.

  $ echo http://google.com/trends | (E=echo\ ;S=sed\ ;read a;x=($($E "$a"|$S's,^\([^:]\+://\)*\([^/]\+\)/\(.*\)$,\1 \2 \3,'));$E"${x[0]}$(i=32;o=0;for x in $(ping -c1 "${x[1]}"|$S's/[^(]\+(//;s/).*//;;s/\./ /g;q');do((o+=(x*(2**(i-=8)))));done;$E$o)/$(for((i=0;i<${#x[2]};i++));do printf "%%%x" "'${x[2]:i:1}";done)")      
  http://3627736174/%74%72%65%6e%64%73

If you use VT100's alternate character sets you might like this character map which shows all the character mappings at once (man console_codes for the idea behind B0UK)

  (((r=255/((${COLUMNS:-$(tput cols)}-16)/18)));C="\e[38;5";Z="\e[0m";A="\e(";for((i=-1;i<r;i++));do X=;for((j=0;c=20,(v=j*r+i),v<256;j++));do((v>r-(\!(i+1)+1)))&&X="$X$C;177m |";((\!(i+1)))&&X="$X$Z 0UKB ddd/ooo/hh"||{(((v>32&&v<127)||v>160))&&printf -v c %x $v;printf -v X "$X $C;160m${A}0\x$c${A}U\x$c${A}K\x$c${A}B\x$c $C;120m%3d$Z/$C;214m%03o$Z/$C;33m%02x" $v $v $v;X=${X//\%/%%};} done;printf "$X\n";done)

Then there's this one I won't tell you about, which #bash suggested I put in the channel bot (!! wow) when I showed them... run it in a 256-color terminal. :P

  E=echo\ ;P=printf\ ;M=$'\e[0m';a(){ $P"\e[38;5;2${z}5;48;5;${1}m %4d $M" $1;};Z=$E$M;for i in 16 93 160;do ((r=(n=\!n)*2-1));for((x=0;x<6;x++,i+=r)) do for((j=0;L=(i+(R=(j/6?17-j:j))*6),z=(R%6>1?3:5),j<12;j++))do a $L;done;$E;done;done;z=5;for i in {0..23};do a $[i+232];((i==11))&&$Z;done;for i in {0..15};do ((i==8||\!i))&&$P'\n%*s' 12;a $i;done;$E

I've written a bidirectional filesystem synchronization tool, and a content management system, in (nearly) pure bash.

I keep expecting the performance to be terrible but it's surprisingly efficient.

The only thing I've found strongly lacking in bash is math. You can `| bc` all you want, but it still seems slow compared to other languages. I typically do all my math in python (typically through pipes... heh), and everything else in bash.

$(( ))?

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