Configuration Information [Automatically generated, do not change]: Machine: x86_64 OS: linux-gnu Compiler: gcc Compilation CFLAGS: -DPROGRAM='bash' -DCONF_HOSTTYPE='x86_64' -DCONF_OSTYPE='linux-gnu' -DCONF_MACHTYPE='x86_64-pc-linux-gnu' -DCONF_VENDOR='pc' -DLOCALEDIR='/usr/share/locale' -DPACKAGE='bash' -DSHELL -DHAVE_CONFIG_H -I. -I../. -I.././include -I.././lib -Wdate-time -D_FORTIFY_SOURCE=2 -g -O2 -fstack-protector-strong -Wformat -Werror=format-security -Wall uname output: Linux x 4.13.0-26-generic #29~16.04.2-Ubuntu SMP Tue Jan 9 22:00:44 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux Machine Type: x86_64-pc-linux-gnu
Bash Version: 4.3
Patch Level: 48
Release Status: release
Description:
Bash unexpectedly evaluates a builtin command argument when it is
executed after `time` keyword. This does not happen when the builtin
command is executed at later time or with different type of argument.
Repeat-By:
Following bash script will trigger the issue.
--------------------[script start]--------------------
#!/bin/bash
if [ "$0" = "$BASH_SOURCE" ]; then
echo "source $0 <cmd>"
exit
fi
if [ ! "$#" = 1 ]; then
echo "[*] missing argument"
return
fi
alias exp='"$($1)"'
echo "[*] type exp: $(type exp)"
echo "[*] executing command: $1"
set -o xtrace
echo exp
time
echo exp
echo exp
--------------------[script end ]--------------------
Example output when the issue occurs:
--------------------[output start]--------------------
$ source ./bashexp.sh "date"
[*] type exp: exp is aliased to `"$($1)"'
[*] executing command: date
++ echo exp
exp
real 0m0.000s
user 0m0.000s
sys 0m0.000s
+++ date
++ echo 'T jaan 16 10:29:24 EET 2018'
T jaan 16 10:29:24 EET 2018
++ echo exp
exp
--------------------[output end ]--------------------
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