printf using in /bin/bash

Question

#!/bin/bash latest_version=\ $((curl -s http://java.com/en/download/installed8.jsp 2>/dev/null || wget -q -O - http://java.com/en/download/installed8.jsp) | grep 'latest8' |sed -E "s/.*= //" |tr -d "';") echo $latest_version printf "%s \n" $latest_version

I want to get a string "1.8.0_102" (as of 2016/7/24)

This shows

#echo 1.8.0_101 #printf 8.0_101

I want to make the string in red and the script will be run in both OS X and linux, so I do not want to use echo.

Why can't I get 1.8.0_101 by printf?

Further more what is wrong with this below?

printf "Get the latest Java \033[1;31m %s \033[m from Oracle.\n" $latest_version

It also does not work...

I have a hint... when I put

latest_version=1.8.0_101

then it works.

so the variable input to latest_version by $() is working wrong?

In the meanwhile I found a shorter solution: latest_version=$((curl -s http://java.com/en/download/installed8.jsp 2>/dev/null || wget -q -O - http://java.com/en/download/installed8.jsp) | grep latest8 | cut -f 2 -d\') — Yaron
– Yaron, Commented Jul 24, 2016 at 11:19
The grep, sed, tr pipe should be a single sed command: sed -n "/latest8/{s/.*= //;s/[';\r]//g;p}" — hek2mgl
– hek2mgl, Commented Jul 24, 2016 at 12:28

Ohad Eytan · Accepted Answer · 2016-07-24 11:40:07Z

If you execute:

printf "%q \n" $latest_version

you get:

$'1.8.0_101\r'

and you can see the redundant \r (carriage returns) character.

To fix this add the \r to your tr command and that will work like a charm:

latest_version=$((curl -s http://java.com/en/download/installed8.jsp 2>/dev/null || wget -q -O - http://java.com/en/download/installed8.jsp) | grep 'latest8' |sed -E "s/.*= //" |tr -d "';\r") printf "%s \n" $latest_version

outputs:

1.8.0_101

@hek2mgl I prefer to answer the OP question with the least modifications to his code so he can understand easily what went wrong
I understand the problem now. Thank you. But how can you see if we have \r in the latest_version in my expression.

anubhava · Accepted Answer · 2016-07-24 11:12:37Z

You can pipe your curl with awk to parse latest version:

latest_version=$(curl -s http://java.com/en/download/installed8.jsp | awk -F= '/latest8/{gsub(/^[^[:digit:]]*|\x27.*$/, "", $2); print $2}')

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