awk syntax errors with double star **

问题

I'm using Debian 6 and GNU sed, trying to get awk to convert the output of du from a long string of bytes to a more human readable number with suffixes like Mb and Kb. (I know you can use the -h option, but I want to do this manually with awk.)

So far, my command looks like this (I put in the newlines to make it more readable):

du /test.img | grep [0-9]* | awk "{ sum=$1 ; hum[1024**3]='Gb';hum[1024**2]='Mb';
hum[1024]='Kb'; for (x=1024**3; x>=1024; x/=1024){ if (sum>=x)
{ printf '%.2f %s\n',sum/x,hum[x];break } }}"

However, I get syntax errors from/near the double stars:

awk: line 1: syntax error at or near *
awk: line 1: syntax error at or near *
awk: line 1: syntax error at or near *
awk: line 1: extra ')'
awk: line 1: syntax error at or near {

If I make all double stars ** just one star *, awk runs, but I get an incorrect number.

What can I do to fix these syntax errors and stop being so awkwardly confused? ba dum tshh

回答1:

Just to make it "official" (as an answer)...

You're using ** for exponentiation. In awk, the ^ operator is used for exponentiation. I imagine there are many references on the internet, but the one I found is here.

来源：https://stackoverflow.com/questions/9913368/awk-syntax-errors-with-double-star