unexpected results from `service

unexpected results from `service | grep`

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$ sudo service --status-all | fgrep -e 'bluetooth'
 [ ? ] alsa-utils
 [ ? ] binfmt-support
 [ + ] bluetooth
 [ ? ] cpufrequtils
 [ ? ] cryptdisks
 [ ? ] cryptdisks-early
 [ ? ] hdparm
 [ ? ] hwclock.sh
 [ ? ] kmod
 [ ? ] loadcpufreq
 [ ? ] networking
 [ ? ] plymouth
 [ ? ] plymouth-log
 [ ? ] pppd-dns
 [ ? ] udev-finish
 [ ? ] virtualbox-guest-x11
$ sudo service bluetooth stop
[ ok ] Stopping bluetooth: /usr/sbin/bluetoothd.
$ sudo service --status-all | fgrep -e 'bluetooth'
 [ ? ] alsa-utils
 [ ? ] binfmt-support
 [ - ] bluetooth
 [ ? ] cpufrequtils
 [ ? ] cryptdisks
 [ ? ] cryptdisks-early
 [ ? ] hdparm
 [ ? ] hwclock.sh
 [ ? ] kmod
 [ ? ] loadcpufreq
 [ ? ] networking
 [ ? ] plymouth
 [ ? ] plymouth-log
 [ ? ] pppd-dns
 [ ? ] udev-finish
 [ ? ] virtualbox-guest-x11

Why am I getting more than 1 output line from service | grep when only 1 line (in each output set) matches the grep pattern? Is there something (bad) magic about the lines beginning [?]? Alternatively, what am I missing?

FWIW, I'm running

$ date
Tue Nov 28 20:51:46 MST 2017
$ uname -rsv
Linux 3.16.0-4-amd64 #1 SMP Debian 3.16.43-2+deb8u5 (2017-09-19)
$ lsb_release -ds
LMDE 2 Betsy
$ cat /etc/debian_version
8.9
$ gcc --version | head -n 1
gcc (Debian 4.9.2-10) 4.9.2

asked Nov 29 '17 at 4:02

TomRoche

4861617

I think you are seeing text which is being written to stderr... try sudo service --status-all 2> /dev/null | fgrep -e 'bluetooth'
â€“Â Sundeep
Nov 29 '17 at 4:14

@Sundeep not on Debian9, all that output is going to stdout for me there
â€“Â thrig
Nov 29 '17 at 4:59

add a commentÂ |Â

up vote
0
down vote

favorite

$ sudo service --status-all | fgrep -e 'bluetooth'
 [ ? ] alsa-utils
 [ ? ] binfmt-support
 [ + ] bluetooth
 [ ? ] cpufrequtils
 [ ? ] cryptdisks
 [ ? ] cryptdisks-early
 [ ? ] hdparm
 [ ? ] hwclock.sh
 [ ? ] kmod
 [ ? ] loadcpufreq
 [ ? ] networking
 [ ? ] plymouth
 [ ? ] plymouth-log
 [ ? ] pppd-dns
 [ ? ] udev-finish
 [ ? ] virtualbox-guest-x11
$ sudo service bluetooth stop
[ ok ] Stopping bluetooth: /usr/sbin/bluetoothd.
$ sudo service --status-all | fgrep -e 'bluetooth'
 [ ? ] alsa-utils
 [ ? ] binfmt-support
 [ - ] bluetooth
 [ ? ] cpufrequtils
 [ ? ] cryptdisks
 [ ? ] cryptdisks-early
 [ ? ] hdparm
 [ ? ] hwclock.sh
 [ ? ] kmod
 [ ? ] loadcpufreq
 [ ? ] networking
 [ ? ] plymouth
 [ ? ] plymouth-log
 [ ? ] pppd-dns
 [ ? ] udev-finish
 [ ? ] virtualbox-guest-x11

FWIW, I'm running

$ date
Tue Nov 28 20:51:46 MST 2017
$ uname -rsv
Linux 3.16.0-4-amd64 #1 SMP Debian 3.16.43-2+deb8u5 (2017-09-19)
$ lsb_release -ds
LMDE 2 Betsy
$ cat /etc/debian_version
8.9
$ gcc --version | head -n 1
gcc (Debian 4.9.2-10) 4.9.2

asked Nov 29 '17 at 4:02

TomRoche

4861617

I think you are seeing text which is being written to stderr... try sudo service --status-all 2> /dev/null | fgrep -e 'bluetooth'
â€“Â Sundeep
Nov 29 '17 at 4:14

@Sundeep not on Debian9, all that output is going to stdout for me there
â€“Â thrig
Nov 29 '17 at 4:59

add a commentÂ |Â

up vote
0
down vote

favorite

$ sudo service --status-all | fgrep -e 'bluetooth'
 [ ? ] alsa-utils
 [ ? ] binfmt-support
 [ + ] bluetooth
 [ ? ] cpufrequtils
 [ ? ] cryptdisks
 [ ? ] cryptdisks-early
 [ ? ] hdparm
 [ ? ] hwclock.sh
 [ ? ] kmod
 [ ? ] loadcpufreq
 [ ? ] networking
 [ ? ] plymouth
 [ ? ] plymouth-log
 [ ? ] pppd-dns
 [ ? ] udev-finish
 [ ? ] virtualbox-guest-x11
$ sudo service bluetooth stop
[ ok ] Stopping bluetooth: /usr/sbin/bluetoothd.
$ sudo service --status-all | fgrep -e 'bluetooth'
 [ ? ] alsa-utils
 [ ? ] binfmt-support
 [ - ] bluetooth
 [ ? ] cpufrequtils
 [ ? ] cryptdisks
 [ ? ] cryptdisks-early
 [ ? ] hdparm
 [ ? ] hwclock.sh
 [ ? ] kmod
 [ ? ] loadcpufreq
 [ ? ] networking
 [ ? ] plymouth
 [ ? ] plymouth-log
 [ ? ] pppd-dns
 [ ? ] udev-finish
 [ ? ] virtualbox-guest-x11

FWIW, I'm running

$ date
Tue Nov 28 20:51:46 MST 2017
$ uname -rsv
Linux 3.16.0-4-amd64 #1 SMP Debian 3.16.43-2+deb8u5 (2017-09-19)
$ lsb_release -ds
LMDE 2 Betsy
$ cat /etc/debian_version
8.9
$ gcc --version | head -n 1
gcc (Debian 4.9.2-10) 4.9.2

asked Nov 29 '17 at 4:02

TomRoche

4861617

$ sudo service --status-all | fgrep -e 'bluetooth'
 [ ? ] alsa-utils
 [ ? ] binfmt-support
 [ + ] bluetooth
 [ ? ] cpufrequtils
 [ ? ] cryptdisks
 [ ? ] cryptdisks-early
 [ ? ] hdparm
 [ ? ] hwclock.sh
 [ ? ] kmod
 [ ? ] loadcpufreq
 [ ? ] networking
 [ ? ] plymouth
 [ ? ] plymouth-log
 [ ? ] pppd-dns
 [ ? ] udev-finish
 [ ? ] virtualbox-guest-x11
$ sudo service bluetooth stop
[ ok ] Stopping bluetooth: /usr/sbin/bluetoothd.
$ sudo service --status-all | fgrep -e 'bluetooth'
 [ ? ] alsa-utils
 [ ? ] binfmt-support
 [ - ] bluetooth
 [ ? ] cpufrequtils
 [ ? ] cryptdisks
 [ ? ] cryptdisks-early
 [ ? ] hdparm
 [ ? ] hwclock.sh
 [ ? ] kmod
 [ ? ] loadcpufreq
 [ ? ] networking
 [ ? ] plymouth
 [ ? ] plymouth-log
 [ ? ] pppd-dns
 [ ? ] udev-finish
 [ ? ] virtualbox-guest-x11

FWIW, I'm running

$ date
Tue Nov 28 20:51:46 MST 2017
$ uname -rsv
Linux 3.16.0-4-amd64 #1 SMP Debian 3.16.43-2+deb8u5 (2017-09-19)
$ lsb_release -ds
LMDE 2 Betsy
$ cat /etc/debian_version
8.9
$ gcc --version | head -n 1
gcc (Debian 4.9.2-10) 4.9.2

asked Nov 29 '17 at 4:02

TomRoche

4861617

asked Nov 29 '17 at 4:02

TomRoche

4861617

asked Nov 29 '17 at 4:02

TomRoche

4861617

asked Nov 29 '17 at 4:02

TomRoche

4861617

I think you are seeing text which is being written to stderr... try sudo service --status-all 2> /dev/null | fgrep -e 'bluetooth'
â€“Â Sundeep
Nov 29 '17 at 4:14

@Sundeep not on Debian9, all that output is going to stdout for me there
â€“Â thrig
Nov 29 '17 at 4:59

add a commentÂ |Â

I think you are seeing text which is being written to stderr... try sudo service --status-all 2> /dev/null | fgrep -e 'bluetooth'
â€“Â Sundeep
Nov 29 '17 at 4:14

@Sundeep not on Debian9, all that output is going to stdout for me there
â€“Â thrig
Nov 29 '17 at 4:59

I think you are seeing text which is being written to stderr... try sudo service --status-all 2> /dev/null | fgrep -e 'bluetooth'
â€“Â Sundeep
Nov 29 '17 at 4:14

@Sundeep not on Debian9, all that output is going to stdout for me there
â€“Â thrig
Nov 29 '17 at 4:59

add a commentÂ |Â

1 Answer
1

active

oldest

votes

up vote
2
down vote

accepted

It appears to me that @Sundeep is correct.

If you look at the script for service there is a redirect that causes this behaviour

if ! is_ignored_file "$SERVICE" 
 && [ -x "$SERVICEDIR/$SERVICE" ]; then
 out=$(env -i LANG="$LANG" LANGUAGE="$LANGUAGE" LC_CTYPE="$LC_CTYPE" LC_NUMERIC="$LC_NUMERIC" LC_TIME="$LC_TIME" LC_COLLATE="$LC_COLLATE" LC_MONETARY="$LC_MONETARY" LC_MESSAGES="$LC_MESSAGES" LC_PAPER="$LC_PAPER" LC_NAME="$LC_NAME" LC_ADDRESS="$LC_ADDRESS" LC_TELEPHONE="$LC_TELEPHONE" LC_MEASUREMENT="$LC_MEASUREMENT" LC_IDENTIFICATION="$LC_IDENTIFICATION" LC_ALL="$LC_ALL" PATH="$PATH" TERM="$TERM" "$SERVICEDIR/$SERVICE" status 2>&1)
 retval=$?
 if echo "$out" | egrep -iq "usage:"; then
 #printf " %s %-60s %sn" "[?]" "$SERVICE:" "unknown" 1>&2
 echo " [ ? ] $SERVICE" 1>&2 #<-------------------HERE
 continue
 else
 if [ "$retval" = "0" -a -n "$out" ]; then
 #printf " %s %-60s %sn" "[+]" "$SERVICE:" "running"
 echo " [ + ] $SERVICE"
 continue
 else
 #printf " %s %-60s %sn" "[-]" "$SERVICE:" "NOT running"
 echo " [ - ] $SERVICE"
 continue
 fi
fi

The redirect is for the error case (a service does not support a call to status) and so while the visible output is [ ? ] the 'juju' is actually the redirect which bypasses the grep.

Testing this on the command line....

~$ echo "banana" | grep bluetooth #nothing echoed
~$ echo "banana" 1>&2 | grep bluetooth #bingo, get a banana
banana

edited Nov 29 '17 at 12:21

answered Nov 29 '17 at 12:16

bu5hman

1,164214

add a commentÂ |Â

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1 Answer
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oldest

votes

1 Answer
1

active

oldest

votes

up vote
2
down vote

accepted

It appears to me that @Sundeep is correct.

If you look at the script for service there is a redirect that causes this behaviour

if ! is_ignored_file "$SERVICE" 
 && [ -x "$SERVICEDIR/$SERVICE" ]; then
 out=$(env -i LANG="$LANG" LANGUAGE="$LANGUAGE" LC_CTYPE="$LC_CTYPE" LC_NUMERIC="$LC_NUMERIC" LC_TIME="$LC_TIME" LC_COLLATE="$LC_COLLATE" LC_MONETARY="$LC_MONETARY" LC_MESSAGES="$LC_MESSAGES" LC_PAPER="$LC_PAPER" LC_NAME="$LC_NAME" LC_ADDRESS="$LC_ADDRESS" LC_TELEPHONE="$LC_TELEPHONE" LC_MEASUREMENT="$LC_MEASUREMENT" LC_IDENTIFICATION="$LC_IDENTIFICATION" LC_ALL="$LC_ALL" PATH="$PATH" TERM="$TERM" "$SERVICEDIR/$SERVICE" status 2>&1)
 retval=$?
 if echo "$out" | egrep -iq "usage:"; then
 #printf " %s %-60s %sn" "[?]" "$SERVICE:" "unknown" 1>&2
 echo " [ ? ] $SERVICE" 1>&2 #<-------------------HERE
 continue
 else
 if [ "$retval" = "0" -a -n "$out" ]; then
 #printf " %s %-60s %sn" "[+]" "$SERVICE:" "running"
 echo " [ + ] $SERVICE"
 continue
 else
 #printf " %s %-60s %sn" "[-]" "$SERVICE:" "NOT running"
 echo " [ - ] $SERVICE"
 continue
 fi
fi

The redirect is for the error case (a service does not support a call to status) and so while the visible output is [ ? ] the 'juju' is actually the redirect which bypasses the grep.

Testing this on the command line....

~$ echo "banana" | grep bluetooth #nothing echoed
~$ echo "banana" 1>&2 | grep bluetooth #bingo, get a banana
banana

edited Nov 29 '17 at 12:21

answered Nov 29 '17 at 12:16

bu5hman

1,164214

add a commentÂ |Â

up vote
2
down vote

accepted

It appears to me that @Sundeep is correct.

If you look at the script for service there is a redirect that causes this behaviour

if ! is_ignored_file "$SERVICE" 
 && [ -x "$SERVICEDIR/$SERVICE" ]; then
 out=$(env -i LANG="$LANG" LANGUAGE="$LANGUAGE" LC_CTYPE="$LC_CTYPE" LC_NUMERIC="$LC_NUMERIC" LC_TIME="$LC_TIME" LC_COLLATE="$LC_COLLATE" LC_MONETARY="$LC_MONETARY" LC_MESSAGES="$LC_MESSAGES" LC_PAPER="$LC_PAPER" LC_NAME="$LC_NAME" LC_ADDRESS="$LC_ADDRESS" LC_TELEPHONE="$LC_TELEPHONE" LC_MEASUREMENT="$LC_MEASUREMENT" LC_IDENTIFICATION="$LC_IDENTIFICATION" LC_ALL="$LC_ALL" PATH="$PATH" TERM="$TERM" "$SERVICEDIR/$SERVICE" status 2>&1)
 retval=$?
 if echo "$out" | egrep -iq "usage:"; then
 #printf " %s %-60s %sn" "[?]" "$SERVICE:" "unknown" 1>&2
 echo " [ ? ] $SERVICE" 1>&2 #<-------------------HERE
 continue
 else
 if [ "$retval" = "0" -a -n "$out" ]; then
 #printf " %s %-60s %sn" "[+]" "$SERVICE:" "running"
 echo " [ + ] $SERVICE"
 continue
 else
 #printf " %s %-60s %sn" "[-]" "$SERVICE:" "NOT running"
 echo " [ - ] $SERVICE"
 continue
 fi
fi

The redirect is for the error case (a service does not support a call to status) and so while the visible output is [ ? ] the 'juju' is actually the redirect which bypasses the grep.

Testing this on the command line....

~$ echo "banana" | grep bluetooth #nothing echoed
~$ echo "banana" 1>&2 | grep bluetooth #bingo, get a banana
banana

edited Nov 29 '17 at 12:21

answered Nov 29 '17 at 12:16

bu5hman

1,164214

add a commentÂ |Â

up vote
2
down vote

accepted

It appears to me that @Sundeep is correct.

If you look at the script for service there is a redirect that causes this behaviour

if ! is_ignored_file "$SERVICE" 
 && [ -x "$SERVICEDIR/$SERVICE" ]; then
 out=$(env -i LANG="$LANG" LANGUAGE="$LANGUAGE" LC_CTYPE="$LC_CTYPE" LC_NUMERIC="$LC_NUMERIC" LC_TIME="$LC_TIME" LC_COLLATE="$LC_COLLATE" LC_MONETARY="$LC_MONETARY" LC_MESSAGES="$LC_MESSAGES" LC_PAPER="$LC_PAPER" LC_NAME="$LC_NAME" LC_ADDRESS="$LC_ADDRESS" LC_TELEPHONE="$LC_TELEPHONE" LC_MEASUREMENT="$LC_MEASUREMENT" LC_IDENTIFICATION="$LC_IDENTIFICATION" LC_ALL="$LC_ALL" PATH="$PATH" TERM="$TERM" "$SERVICEDIR/$SERVICE" status 2>&1)
 retval=$?
 if echo "$out" | egrep -iq "usage:"; then
 #printf " %s %-60s %sn" "[?]" "$SERVICE:" "unknown" 1>&2
 echo " [ ? ] $SERVICE" 1>&2 #<-------------------HERE
 continue
 else
 if [ "$retval" = "0" -a -n "$out" ]; then
 #printf " %s %-60s %sn" "[+]" "$SERVICE:" "running"
 echo " [ + ] $SERVICE"
 continue
 else
 #printf " %s %-60s %sn" "[-]" "$SERVICE:" "NOT running"
 echo " [ - ] $SERVICE"
 continue
 fi
fi

The redirect is for the error case (a service does not support a call to status) and so while the visible output is [ ? ] the 'juju' is actually the redirect which bypasses the grep.

Testing this on the command line....

~$ echo "banana" | grep bluetooth #nothing echoed
~$ echo "banana" 1>&2 | grep bluetooth #bingo, get a banana
banana

edited Nov 29 '17 at 12:21

answered Nov 29 '17 at 12:16

bu5hman

1,164214

It appears to me that @Sundeep is correct.

If you look at the script for service there is a redirect that causes this behaviour

if ! is_ignored_file "$SERVICE" 
 && [ -x "$SERVICEDIR/$SERVICE" ]; then
 out=$(env -i LANG="$LANG" LANGUAGE="$LANGUAGE" LC_CTYPE="$LC_CTYPE" LC_NUMERIC="$LC_NUMERIC" LC_TIME="$LC_TIME" LC_COLLATE="$LC_COLLATE" LC_MONETARY="$LC_MONETARY" LC_MESSAGES="$LC_MESSAGES" LC_PAPER="$LC_PAPER" LC_NAME="$LC_NAME" LC_ADDRESS="$LC_ADDRESS" LC_TELEPHONE="$LC_TELEPHONE" LC_MEASUREMENT="$LC_MEASUREMENT" LC_IDENTIFICATION="$LC_IDENTIFICATION" LC_ALL="$LC_ALL" PATH="$PATH" TERM="$TERM" "$SERVICEDIR/$SERVICE" status 2>&1)
 retval=$?
 if echo "$out" | egrep -iq "usage:"; then
 #printf " %s %-60s %sn" "[?]" "$SERVICE:" "unknown" 1>&2
 echo " [ ? ] $SERVICE" 1>&2 #<-------------------HERE
 continue
 else
 if [ "$retval" = "0" -a -n "$out" ]; then
 #printf " %s %-60s %sn" "[+]" "$SERVICE:" "running"
 echo " [ + ] $SERVICE"
 continue
 else
 #printf " %s %-60s %sn" "[-]" "$SERVICE:" "NOT running"
 echo " [ - ] $SERVICE"
 continue
 fi
fi

The redirect is for the error case (a service does not support a call to status) and so while the visible output is [ ? ] the 'juju' is actually the redirect which bypasses the grep.

Testing this on the command line....

~$ echo "banana" | grep bluetooth #nothing echoed
~$ echo "banana" 1>&2 | grep bluetooth #bingo, get a banana
banana

edited Nov 29 '17 at 12:21

answered Nov 29 '17 at 12:16

bu5hman

1,164214

edited Nov 29 '17 at 12:21

answered Nov 29 '17 at 12:16

bu5hman

1,164214

answered Nov 29 '17 at 12:16

bu5hman

1,164214

answered Nov 29 '17 at 12:16

bu5hman

1,164214

add a commentÂ |Â

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