Running multiple commands with su in Bash

up vote
8
down vote

favorite

I would like to use su -c to run as root multiple commands altogether. I don't want to use an extra script for this.

I tried the following:

su root -c "tcpdump -i wlan0 -s 1500 -w CCCCCC & " -c "ls -lh"

but it executes only the ls not the first one.

I tried the following:

su root -c "tcpdump -i wlan0 -s 1500 -w CCCCCC & ; ls -lh;"

but it says that there is an error with the semicolon ;.

Do you know how to do that?

edited Feb 15 '17 at 19:46

codeforester

368314

asked Apr 4 '11 at 14:14

Abruzzo Forte e Gentile

194136

migrated from stackoverflow.com Apr 4 '11 at 20:00

This question came from our site for professional and enthusiast programmers.

add a comment |

up vote
8
down vote

favorite

I would like to use su -c to run as root multiple commands altogether. I don't want to use an extra script for this.

I tried the following:

su root -c "tcpdump -i wlan0 -s 1500 -w CCCCCC & " -c "ls -lh"

but it executes only the ls not the first one.

I tried the following:

su root -c "tcpdump -i wlan0 -s 1500 -w CCCCCC & ; ls -lh;"

but it says that there is an error with the semicolon ;.

Do you know how to do that?

edited Feb 15 '17 at 19:46

codeforester

368314

asked Apr 4 '11 at 14:14

Abruzzo Forte e Gentile

194136

migrated from stackoverflow.com Apr 4 '11 at 20:00

This question came from our site for professional and enthusiast programmers.

add a comment |

up vote
8
down vote

favorite

I would like to use su -c to run as root multiple commands altogether. I don't want to use an extra script for this.

I tried the following:

su root -c "tcpdump -i wlan0 -s 1500 -w CCCCCC & " -c "ls -lh"

but it executes only the ls not the first one.

I tried the following:

su root -c "tcpdump -i wlan0 -s 1500 -w CCCCCC & ; ls -lh;"

but it says that there is an error with the semicolon ;.

Do you know how to do that?

edited Feb 15 '17 at 19:46

codeforester

368314

asked Apr 4 '11 at 14:14

Abruzzo Forte e Gentile

194136

I would like to use su -c to run as root multiple commands altogether. I don't want to use an extra script for this.

I tried the following:

su root -c "tcpdump -i wlan0 -s 1500 -w CCCCCC & " -c "ls -lh"

but it executes only the ls not the first one.

I tried the following:

su root -c "tcpdump -i wlan0 -s 1500 -w CCCCCC & ; ls -lh;"

but it says that there is an error with the semicolon ;.

Do you know how to do that?

bash su

edited Feb 15 '17 at 19:46

codeforester

368314

asked Apr 4 '11 at 14:14

Abruzzo Forte e Gentile

194136

edited Feb 15 '17 at 19:46

codeforester

368314

asked Apr 4 '11 at 14:14

Abruzzo Forte e Gentile

194136

edited Feb 15 '17 at 19:46

codeforester

368314

edited Feb 15 '17 at 19:46

codeforester

368314

edited Feb 15 '17 at 19:46

codeforester

368314

asked Apr 4 '11 at 14:14

Abruzzo Forte e Gentile

194136

asked Apr 4 '11 at 14:14

Abruzzo Forte e Gentile

194136

asked Apr 4 '11 at 14:14

Abruzzo Forte e Gentile

194136

migrated from stackoverflow.com Apr 4 '11 at 20:00

This question came from our site for professional and enthusiast programmers.

migrated from stackoverflow.com Apr 4 '11 at 20:00

This question came from our site for professional and enthusiast programmers.

add a comment |

5 Answers
5

active

oldest

votes

up vote
12
down vote

accepted

This command runs fine:

su root -c "date; ls -lh"

But in this command:

su root -c "tcpdump -i wlan0 -s 1500 -w CCCCCC & ; ls -lh;"

Since you have & before ; therefore you are getting errors. Try removing & and re-executing the command.

Or you can run your command like this:

su root -c "(tcpdump -i wlan0 -s 1500 -w CCCCCC &); ls -lh"

answered Apr 4 '11 at 14:20

anubhava

36135

Of course, there’s no reason to add parentheses unless the OP really really really wants to type a ; between the tcpdump and ls commands — just leave out the semicolons and it will work.
– G-Man
Feb 15 '17 at 20:04

add a comment |

up vote
2
down vote

As anubhava says, your

su root -c "tcpdump -i wlan0 -s 1500 -w CCCCCC & ; ls -lh;"

command is failing because you’re not allowed to have
& followed immediately by ;.
You can see this just by typing the commands directly into the shell:

true & true works

true & ; true doesn’t work

If you want the tcpdump command to run in the background,
remove the ;, as in

su root -c "tcpdump -i wlan0 -s 1500 -w CCCCCC & ls -lh;"

(and you don't need the ; at the end, either, but it doesn’t hurt).

edited Apr 13 '17 at 12:36

Community♦

answered Feb 15 '17 at 19:57

G-Man

12.3k92961

add a comment |

up vote
1
down vote

I think the nohup command will get you what you want too... tcpdump running in the background (no ampersand necessary):

su root -c "nohup tcpdump -i wlan0 -s 1500 -w CCCCCC ; ls -lh"

answered Apr 4 '11 at 14:38

mcmap

Hi I think so. NOHUP leaves commands running in background even when a user disconnect. I didn't remember that. Thanks a lot.
– Abruzzo Forte e Gentile
Apr 4 '11 at 15:34

(1) It’s good to use nohup when you run commands in the background, but that really has nothing to do with this question. (2) This answer is wrong — nohup by itself does not cause a command to run in the background; you still have to type & (which leaves us back where we started, with a syntax error in the command).
– G-Man
Feb 15 '17 at 20:11

add a comment |

up vote
0
down vote

Just to add to Anubhava's excellent answer:

You could use as well, like this:

su root -c " tcpdump -i wlan0 -s 1500 -w CCCCCC & ; ls -lh"

is a little more efficient than () in that it doesn't create a sub shell. does need a space after and a ; before unless we have an & already.

edited Apr 13 '17 at 12:36

Community♦

answered Feb 15 '17 at 19:34

codeforester

368314

Of course, there’s no reason to add braces or parentheses at all unless the user really really really wants to type a ; between the tcpdump and ls commands — just leave out the semicolon and it will work.
– G-Man
Feb 15 '17 at 20:05

add a comment |

up vote
-1
down vote

Use && to separate your commands like so:

$ su -c "ls && ls"

answered Apr 4 '11 at 14:20

nickgrim

Auch..that's my error. I wanted to run the process in background but I was not aware of this && to separate commands. Thx
– Abruzzo Forte e Gentile
Apr 4 '11 at 15:35

2

&& means "Only execute the second command if the first succeeded". If your first command errors out, the second one won't run. This is usually good, but I would hesitate to describe && as purely a separator.
– Leons
Feb 21 '13 at 15:50

And, if you want to run the tcpdump process in the background, && does you no good whatsoever.
– G-Man
Feb 15 '17 at 20:14

add a comment |

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5 Answers
5

active

oldest

votes

5 Answers
5

active

oldest

votes

up vote
12
down vote

accepted

This command runs fine:

su root -c "date; ls -lh"

But in this command:

su root -c "tcpdump -i wlan0 -s 1500 -w CCCCCC & ; ls -lh;"

Since you have & before ; therefore you are getting errors. Try removing & and re-executing the command.

Or you can run your command like this:

su root -c "(tcpdump -i wlan0 -s 1500 -w CCCCCC &); ls -lh"

answered Apr 4 '11 at 14:20

anubhava

36135

Of course, there’s no reason to add parentheses unless the OP really really really wants to type a ; between the tcpdump and ls commands — just leave out the semicolons and it will work.
– G-Man
Feb 15 '17 at 20:04

add a comment |

up vote
12
down vote

accepted

This command runs fine:

su root -c "date; ls -lh"

But in this command:

su root -c "tcpdump -i wlan0 -s 1500 -w CCCCCC & ; ls -lh;"

Since you have & before ; therefore you are getting errors. Try removing & and re-executing the command.

Or you can run your command like this:

su root -c "(tcpdump -i wlan0 -s 1500 -w CCCCCC &); ls -lh"

answered Apr 4 '11 at 14:20

anubhava

36135

Of course, there’s no reason to add parentheses unless the OP really really really wants to type a ; between the tcpdump and ls commands — just leave out the semicolons and it will work.
– G-Man
Feb 15 '17 at 20:04

add a comment |

up vote
12
down vote

accepted

This command runs fine:

su root -c "date; ls -lh"

But in this command:

su root -c "tcpdump -i wlan0 -s 1500 -w CCCCCC & ; ls -lh;"

Since you have & before ; therefore you are getting errors. Try removing & and re-executing the command.

Or you can run your command like this:

su root -c "(tcpdump -i wlan0 -s 1500 -w CCCCCC &); ls -lh"

answered Apr 4 '11 at 14:20

anubhava

36135

This command runs fine:

su root -c "date; ls -lh"

But in this command:

su root -c "tcpdump -i wlan0 -s 1500 -w CCCCCC & ; ls -lh;"

Since you have & before ; therefore you are getting errors. Try removing & and re-executing the command.

Or you can run your command like this:

su root -c "(tcpdump -i wlan0 -s 1500 -w CCCCCC &); ls -lh"

answered Apr 4 '11 at 14:20

anubhava

36135

answered Apr 4 '11 at 14:20

anubhava

36135

answered Apr 4 '11 at 14:20

anubhava

36135

answered Apr 4 '11 at 14:20

anubhava

36135

Of course, there’s no reason to add parentheses unless the OP really really really wants to type a ; between the tcpdump and ls commands — just leave out the semicolons and it will work.
– G-Man
Feb 15 '17 at 20:04

add a comment |

Of course, there’s no reason to add parentheses unless the OP really really really wants to type a ; between the tcpdump and ls commands — just leave out the semicolons and it will work.
– G-Man
Feb 15 '17 at 20:04

Of course, there’s no reason to add parentheses unless the OP really really really wants to type a ; between the tcpdump and ls commands — just leave out the semicolons and it will work.
– G-Man
Feb 15 '17 at 20:04

add a comment |

up vote
2
down vote

As anubhava says, your

su root -c "tcpdump -i wlan0 -s 1500 -w CCCCCC & ; ls -lh;"

command is failing because you’re not allowed to have
& followed immediately by ;.
You can see this just by typing the commands directly into the shell:

true & true works

true & ; true doesn’t work

If you want the tcpdump command to run in the background,
remove the ;, as in

su root -c "tcpdump -i wlan0 -s 1500 -w CCCCCC & ls -lh;"

(and you don't need the ; at the end, either, but it doesn’t hurt).

edited Apr 13 '17 at 12:36

Community♦

answered Feb 15 '17 at 19:57

G-Man

12.3k92961

add a comment |

up vote
2
down vote

As anubhava says, your

su root -c "tcpdump -i wlan0 -s 1500 -w CCCCCC & ; ls -lh;"

command is failing because you’re not allowed to have
& followed immediately by ;.
You can see this just by typing the commands directly into the shell:

true & true works

true & ; true doesn’t work

If you want the tcpdump command to run in the background,
remove the ;, as in

su root -c "tcpdump -i wlan0 -s 1500 -w CCCCCC & ls -lh;"

(and you don't need the ; at the end, either, but it doesn’t hurt).

edited Apr 13 '17 at 12:36

Community♦

answered Feb 15 '17 at 19:57

G-Man

12.3k92961

add a comment |

up vote
2
down vote

As anubhava says, your

su root -c "tcpdump -i wlan0 -s 1500 -w CCCCCC & ; ls -lh;"

command is failing because you’re not allowed to have
& followed immediately by ;.
You can see this just by typing the commands directly into the shell:

true & true works

true & ; true doesn’t work

If you want the tcpdump command to run in the background,
remove the ;, as in

su root -c "tcpdump -i wlan0 -s 1500 -w CCCCCC & ls -lh;"

(and you don't need the ; at the end, either, but it doesn’t hurt).

edited Apr 13 '17 at 12:36

Community♦

answered Feb 15 '17 at 19:57

G-Man

12.3k92961

As anubhava says, your

su root -c "tcpdump -i wlan0 -s 1500 -w CCCCCC & ; ls -lh;"

command is failing because you’re not allowed to have
& followed immediately by ;.
You can see this just by typing the commands directly into the shell:

true & true works

true & ; true doesn’t work

If you want the tcpdump command to run in the background,
remove the ;, as in

su root -c "tcpdump -i wlan0 -s 1500 -w CCCCCC & ls -lh;"

(and you don't need the ; at the end, either, but it doesn’t hurt).

edited Apr 13 '17 at 12:36

Community♦

answered Feb 15 '17 at 19:57

G-Man

12.3k92961

edited Apr 13 '17 at 12:36

Community♦

edited Apr 13 '17 at 12:36

Community♦

edited Apr 13 '17 at 12:36

Community♦

answered Feb 15 '17 at 19:57

G-Man

12.3k92961

answered Feb 15 '17 at 19:57

G-Man

12.3k92961

answered Feb 15 '17 at 19:57

G-Man

12.3k92961

add a comment |

up vote
1
down vote

I think the nohup command will get you what you want too... tcpdump running in the background (no ampersand necessary):

su root -c "nohup tcpdump -i wlan0 -s 1500 -w CCCCCC ; ls -lh"

answered Apr 4 '11 at 14:38

mcmap

Hi I think so. NOHUP leaves commands running in background even when a user disconnect. I didn't remember that. Thanks a lot.
– Abruzzo Forte e Gentile
Apr 4 '11 at 15:34

(1) It’s good to use nohup when you run commands in the background, but that really has nothing to do with this question. (2) This answer is wrong — nohup by itself does not cause a command to run in the background; you still have to type & (which leaves us back where we started, with a syntax error in the command).
– G-Man
Feb 15 '17 at 20:11

add a comment |

up vote
1
down vote

I think the nohup command will get you what you want too... tcpdump running in the background (no ampersand necessary):

su root -c "nohup tcpdump -i wlan0 -s 1500 -w CCCCCC ; ls -lh"

answered Apr 4 '11 at 14:38

mcmap

Hi I think so. NOHUP leaves commands running in background even when a user disconnect. I didn't remember that. Thanks a lot.
– Abruzzo Forte e Gentile
Apr 4 '11 at 15:34

(1) It’s good to use nohup when you run commands in the background, but that really has nothing to do with this question. (2) This answer is wrong — nohup by itself does not cause a command to run in the background; you still have to type & (which leaves us back where we started, with a syntax error in the command).
– G-Man
Feb 15 '17 at 20:11

add a comment |

up vote
1
down vote

I think the nohup command will get you what you want too... tcpdump running in the background (no ampersand necessary):

su root -c "nohup tcpdump -i wlan0 -s 1500 -w CCCCCC ; ls -lh"

answered Apr 4 '11 at 14:38

mcmap

I think the nohup command will get you what you want too... tcpdump running in the background (no ampersand necessary):

su root -c "nohup tcpdump -i wlan0 -s 1500 -w CCCCCC ; ls -lh"

answered Apr 4 '11 at 14:38

mcmap

answered Apr 4 '11 at 14:38

mcmap

answered Apr 4 '11 at 14:38

mcmap

answered Apr 4 '11 at 14:38

mcmap

Hi I think so. NOHUP leaves commands running in background even when a user disconnect. I didn't remember that. Thanks a lot.
– Abruzzo Forte e Gentile
Apr 4 '11 at 15:34

(1) It’s good to use nohup when you run commands in the background, but that really has nothing to do with this question. (2) This answer is wrong — nohup by itself does not cause a command to run in the background; you still have to type & (which leaves us back where we started, with a syntax error in the command).
– G-Man
Feb 15 '17 at 20:11

add a comment |

Hi I think so. NOHUP leaves commands running in background even when a user disconnect. I didn't remember that. Thanks a lot.
– Abruzzo Forte e Gentile
Apr 4 '11 at 15:34

(1) It’s good to use nohup when you run commands in the background, but that really has nothing to do with this question. (2) This answer is wrong — nohup by itself does not cause a command to run in the background; you still have to type & (which leaves us back where we started, with a syntax error in the command).
– G-Man
Feb 15 '17 at 20:11

Hi I think so. NOHUP leaves commands running in background even when a user disconnect. I didn't remember that. Thanks a lot.
– Abruzzo Forte e Gentile
Apr 4 '11 at 15:34

(1) It’s good to use nohup when you run commands in the background, but that really has nothing to do with this question. (2) This answer is wrong — nohup by itself does not cause a command to run in the background; you still have to type & (which leaves us back where we started, with a syntax error in the command).
– G-Man
Feb 15 '17 at 20:11

add a comment |

up vote
0
down vote

Just to add to Anubhava's excellent answer:

You could use as well, like this:

su root -c " tcpdump -i wlan0 -s 1500 -w CCCCCC & ; ls -lh"

is a little more efficient than () in that it doesn't create a sub shell. does need a space after and a ; before unless we have an & already.

edited Apr 13 '17 at 12:36

Community♦

answered Feb 15 '17 at 19:34

codeforester

368314

Of course, there’s no reason to add braces or parentheses at all unless the user really really really wants to type a ; between the tcpdump and ls commands — just leave out the semicolon and it will work.
– G-Man
Feb 15 '17 at 20:05

add a comment |

up vote
0
down vote

Just to add to Anubhava's excellent answer:

You could use as well, like this:

su root -c " tcpdump -i wlan0 -s 1500 -w CCCCCC & ; ls -lh"

is a little more efficient than () in that it doesn't create a sub shell. does need a space after and a ; before unless we have an & already.

edited Apr 13 '17 at 12:36

Community♦

answered Feb 15 '17 at 19:34

codeforester

368314

Of course, there’s no reason to add braces or parentheses at all unless the user really really really wants to type a ; between the tcpdump and ls commands — just leave out the semicolon and it will work.
– G-Man
Feb 15 '17 at 20:05

add a comment |

up vote
0
down vote

Just to add to Anubhava's excellent answer:

You could use as well, like this:

su root -c " tcpdump -i wlan0 -s 1500 -w CCCCCC & ; ls -lh"

is a little more efficient than () in that it doesn't create a sub shell. does need a space after and a ; before unless we have an & already.

edited Apr 13 '17 at 12:36

Community♦

answered Feb 15 '17 at 19:34

codeforester

368314

Just to add to Anubhava's excellent answer:

You could use as well, like this:

su root -c " tcpdump -i wlan0 -s 1500 -w CCCCCC & ; ls -lh"

is a little more efficient than () in that it doesn't create a sub shell. does need a space after and a ; before unless we have an & already.

edited Apr 13 '17 at 12:36

Community♦

answered Feb 15 '17 at 19:34

codeforester

368314

edited Apr 13 '17 at 12:36

Community♦

edited Apr 13 '17 at 12:36

Community♦

edited Apr 13 '17 at 12:36

Community♦

answered Feb 15 '17 at 19:34

codeforester

368314

answered Feb 15 '17 at 19:34

codeforester

368314

answered Feb 15 '17 at 19:34

codeforester

368314

Of course, there’s no reason to add braces or parentheses at all unless the user really really really wants to type a ; between the tcpdump and ls commands — just leave out the semicolon and it will work.
– G-Man
Feb 15 '17 at 20:05

add a comment |

Of course, there’s no reason to add braces or parentheses at all unless the user really really really wants to type a ; between the tcpdump and ls commands — just leave out the semicolon and it will work.
– G-Man
Feb 15 '17 at 20:05

Of course, there’s no reason to add braces or parentheses at all unless the user really really really wants to type a ; between the tcpdump and ls commands — just leave out the semicolon and it will work.
– G-Man
Feb 15 '17 at 20:05

add a comment |

up vote
-1
down vote

Use && to separate your commands like so:

$ su -c "ls && ls"

answered Apr 4 '11 at 14:20

nickgrim

Auch..that's my error. I wanted to run the process in background but I was not aware of this && to separate commands. Thx
– Abruzzo Forte e Gentile
Apr 4 '11 at 15:35

2

&& means "Only execute the second command if the first succeeded". If your first command errors out, the second one won't run. This is usually good, but I would hesitate to describe && as purely a separator.
– Leons
Feb 21 '13 at 15:50

And, if you want to run the tcpdump process in the background, && does you no good whatsoever.
– G-Man
Feb 15 '17 at 20:14

add a comment |

up vote
-1
down vote

Use && to separate your commands like so:

$ su -c "ls && ls"

answered Apr 4 '11 at 14:20

nickgrim

Auch..that's my error. I wanted to run the process in background but I was not aware of this && to separate commands. Thx
– Abruzzo Forte e Gentile
Apr 4 '11 at 15:35

2

&& means "Only execute the second command if the first succeeded". If your first command errors out, the second one won't run. This is usually good, but I would hesitate to describe && as purely a separator.
– Leons
Feb 21 '13 at 15:50

And, if you want to run the tcpdump process in the background, && does you no good whatsoever.
– G-Man
Feb 15 '17 at 20:14

add a comment |

up vote
-1
down vote

Use && to separate your commands like so:

$ su -c "ls && ls"

answered Apr 4 '11 at 14:20

nickgrim

Use && to separate your commands like so:

$ su -c "ls && ls"

answered Apr 4 '11 at 14:20

nickgrim

answered Apr 4 '11 at 14:20

nickgrim

answered Apr 4 '11 at 14:20

nickgrim

answered Apr 4 '11 at 14:20

nickgrim

Auch..that's my error. I wanted to run the process in background but I was not aware of this && to separate commands. Thx
– Abruzzo Forte e Gentile
Apr 4 '11 at 15:35

2

&& means "Only execute the second command if the first succeeded". If your first command errors out, the second one won't run. This is usually good, but I would hesitate to describe && as purely a separator.
– Leons
Feb 21 '13 at 15:50

And, if you want to run the tcpdump process in the background, && does you no good whatsoever.
– G-Man
Feb 15 '17 at 20:14

add a comment |

Auch..that's my error. I wanted to run the process in background but I was not aware of this && to separate commands. Thx
– Abruzzo Forte e Gentile
Apr 4 '11 at 15:35

2

&& means "Only execute the second command if the first succeeded". If your first command errors out, the second one won't run. This is usually good, but I would hesitate to describe && as purely a separator.
– Leons
Feb 21 '13 at 15:50

And, if you want to run the tcpdump process in the background, && does you no good whatsoever.
– G-Man
Feb 15 '17 at 20:14

Auch..that's my error. I wanted to run the process in background but I was not aware of this && to separate commands. Thx
– Abruzzo Forte e Gentile
Apr 4 '11 at 15:35

&& means "Only execute the second command if the first succeeded". If your first command errors out, the second one won't run. This is usually good, but I would hesitate to describe && as purely a separator.
– Leons
Feb 21 '13 at 15:50

And, if you want to run the tcpdump process in the background, && does you no good whatsoever.
– G-Man
Feb 15 '17 at 20:14

add a comment |

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