SC3029 – ShellCheck Wiki

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In POSIX sh, |& in place of 2>&1 | is undefined.

Problematic code:

make |& tee ~/log

Correct code:

Either switch to bash:

make 2>&1 | tee ~/log


Your script uses a shell feature not supported by the shebang. Either rewrite the script to be portable, or change the shebang to explicitly require a shell like Bash.

In this case, the non-portable shorthand |& to pipe both stdout and stderr can be easily replaced with its written out form 2>&1 | as shown.



ShellCheck is a static analysis tool for shell scripts. This page is part of its documentation.