I'm trying to replace floating-point numbers like 1.2e + 3 with their integer value 1200. For this I use sed in the following way:
echo '"1.2e+04"' | sed "s/\"\([0-9]\+\.[0-9]\+\)e+\([0-9]\+\)\"/$(echo \1*10^\2|bc -l)/"
but the pattern parts \1 and \2 doesn't get evaluated in the echo.
Is there a way to solve this problem with sed? Thanks in advance
Within the double quotes, \1 and \2 are interpreted as literal 1 and 2.
You need to put additional backslashes to escape them. In addition, $(command substitution) in
sed replacement seems not to work when combined with back references.
If you are using GNU sed, you can instead say something like:
echo '"1.2e+04"' | sed "s/\"\([0-9]\+\.[0-9]\+\)e+\([0-9]\+\)\"/echo \"\\1*10^\\2\"|bc -l/;e"
which yields:
12000.0
If you want to chop off the decimal point, you'll know what to do ;-).