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
-D_FORTIFY_SOURCE=2 -g -O2 -fstack-protector-strong -Wformat
-Werror=format-security -Wall
uname output: Linux admin-laptop-debian 4.4.0 #4 SMP Sat May 14 22:23:09
EEST 2016 x86_64 GNU/Linux
Machine Type: x86_64-pc-linux-gnu
Bash Version: 4.3
Patch Level: 42
Release Status: release
Description:
The read builtin disregards (or sporadically uses unpredictable value of)
the IFS variable when is interrupted by a trapped signal.
Repeat-By:
- install a trap for a signal, say SIGALRM or SIGUSR1
- cycle read from a process with a custom IFS to split read string into
variables
- each interrupted read will return the string splitted in wrong way
Attached script demonstrates the bug.
Thank you in advance.
With best regards,
Andriy Martynets
#!/bin/bash
ring()
{
:
}
trap ring SIGALRM
{
while true
do
sleep 2
kill -s SIGALRM $$
done
} & # run an "alarm clock" that rings the parent every second second
while IFS=$'=' read key value
# while read key
do
# value=${key#*=}
# key=${key%%=*}
echo Read: key=\"$key\" value=\"$value\"
done < <(
# This is to emulate a process which output we read
while true
do
sleep 1
echo key=value
done
)
exit
