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Update bash-gotchas.md

David Stark committed 2020-06-02 01:11:43 +0100 commit 9bbaea4515d7053395c06e06e7912c668e6197c2

				compute/bash-gotchas.md
			
          @@ -2,8 +2,9 @@

           This kind of shit is why sysadmins drink.

           ### (( )) can return false 

          -[Iff](https://en.wikipedia.org/wiki/If_and_only_if) the expression in (( )) evaluates to 0, the (( )) returns false, so your 'set -e' script will fall on its arse.

          +[Iff](https://en.wikipedia.org/wiki/If_and_only_if) the expression in `(( blah ))` evaluates to 0, the `(( ))` returns false, so your `set -e` script will fall on its arse.

           ### pipes into read can return false

          -In some old versions of bash (e.g. RHEL6), piping commands into `while read -r blah` will fail at the end of the stream.

          +In some old versions of bash (e.g. RHEL6), piping commands into `while read -r blah` will fail at the end of the stream, so `set -e` will make a mockery of you.

          +

           Use `while read -r blah; do something; done < <(command>)` instead.

...	...	@@ -2,8 +2,9 @@
2	2	This kind of shit is why sysadmins drink.
3	3
4	4	### (( )) can return false
5		-[Iff](https://en.wikipedia.org/wiki/If_and_only_if) the expression in (( )) evaluates to 0, the (( )) returns false, so your 'set -e' script will fall on its arse.
	5	+[Iff](https://en.wikipedia.org/wiki/If_and_only_if) the expression in `(( blah ))` evaluates to 0, the `(( ))` returns false, so your `set -e` script will fall on its arse.
6	6
7	7	### pipes into read can return false
8		-In some old versions of bash (e.g. RHEL6), piping commands into `while read -r blah` will fail at the end of the stream.
	8	+In some old versions of bash (e.g. RHEL6), piping commands into `while read -r blah` will fail at the end of the stream, so `set -e` will make a mockery of you.
	9	+
9	10	Use `while read -r blah; do something; done < <(command>)` instead.