Bash: failed to read from a pipe

Asked Jul 27 '20 at 18:33

Active Jul 27 '20 at 18:33

Viewed 29 times

On my Linux system, I want to generate a MD5 check sum and save it to a variable. The command to generate check sum is:

$ md5sum myfile.zip

And the output is:

060906cec6fd1037ff275d928f96b419  myfile.zip

I want to pipe this output into a read command like so:

$ md5sum myfile.zip | read sum filename

However, that does not seem to work: the variables sum and filename remains undefined. I worked around this problem by redirecting the output into a file, then read it back:

$ md5sum myfile.zip > tempfile
$ read sum filename < tempfile

What did I do wrong and how do I fix it? I appreciate your answers and comments.

asked Jul 27 '20 at 18:33

Hai Vu

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The *already answered* question does not address my question. The comments from Inian and M. Nejat Aydin do. If you create the answer, I'll upvote. – Hai Vu Jul 27 '20 at 18:46
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It does address your question. The accepted answer shows why and how to use process substitution here, and even offers alternatives. – oguz ismail Jul 27 '20 at 18:48
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I take back: it does addressed my question. Thank you, @oguzismail – Hai Vu Jul 27 '20 at 18:51
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Try `read sum filename << – Wiimm Jul 27 '20 at 22:17
@Wiimm That also works. Thank you. – Hai Vu Jul 28 '20 at 19:10

Bash: failed to read from a pipe

0 Answers0