I'm trying to script the download of the node.js source and corresponding SHASUMS256.txt, checksum it, grep for OK, and return no results just exit code 0 on success using grep's -q flag:
wget http://nodejs.org/dist/latest/node-v0.10.26.tar.gz
wget http://nodejs.org/dist/latest/SHASUMS256.txt
sha256sum -c SHASUMS256.txt|grep -q OK
However, grep is returning a selection of the non-matching lines "no such file or directory" errors (though not all, confusingly):
> sha256sum -c SHASUMS256.txt|grep -q OK
sha256sum: node-v0.10.26-darwin-x64.tar.gz: No such file or directory
sha256sum: node-v0.10.26-darwin-x86.tar.gz: No such file or directory
sha256sum: node-v0.10.26-linux-x64.tar.gz: No such file or directory
sha256sum: node-v0.10.26-linux-x86.tar.gz: No such file or directory
sha256sum: node-v0.10.26-sunos-x64.tar.gz: No such file or directory
sha256sum: node-v0.10.26-sunos-x86.tar.gz: No such file or directory
sha256sum: node-v0.10.26-x86.msi: No such file or directory
sha256sum: node-v0.10.26.pkg: No such file or directory
sha256sum: node.exe: No such file or directory
Any idea what the problem is here? All I want from this script is return code 0 if the checksum succeeds (eg grep matches OK), or return code non-0 if it fails.