Multi-line, double quoted string triggers history expansion on subsequent single-quoted commands it gets piped to

[Néstor Tejero]

Hello,

This is my system:

$ bash --version

GNU bash, version 4.3.11(1)-release (x86_64-pc-linux-gnu)

$ uname -a

Linux PCNTEJERO 3.19.0-51-generic #58~14.04.1-Ubuntu SMP Fri Feb 26 22:02:58 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux

ntejero@PCNTEJERO: ~

$ cat /etc/*ease

DISTRIB_ID=LinuxMint

DISTRIB_RELEASE=17.3

DISTRIB_CODENAME=rosa

DISTRIB_DESCRIPTION="Linux Mint 17.3 Rosa"

NAME="Ubuntu"

VERSION="14.04.4 LTS, Trusty Tahr"

ID=ubuntu

ID_LIKE=debian

PRETTY_NAME="Ubuntu 14.04.4 LTS"

VERSION_ID="14.04"

HOME_URL="http://www.ubuntu.com/"

SUPPORT_URL="http://help.ubuntu.com/"

BUG_REPORT_URL="http://bugs.launchpad.net/ubuntu/"

cat: /etc/upstream-release: Is a directory

Bash was installed through "apt-get install --only-upgrade bash"

The bug:

When printing a multi-line string and piping to another command that uses single-quotes, Bash tries to perform history expansion:

echo "9

> 10

> 9

> 11" | awk '!seen[$0]++'

bash: !seen[$0]++': event not found

> 

$ echo "9

> 10

> 11" | echo '!a'

bash: !a': event not found

> 

Turning history off solves it, but anyway history expansion should not occur within single-quotes. This does not happen in single lines:

$ printf "23\n24\n25" | echo '!a'

!a

Néstor