How do I identify the “sudo … †command output format?
Multi tool use
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I am enclosing bash -x output which shows that the command "sudo iwlist wlan0 scan" was executed and returned expected text to terminal .
The issue is - this text was not passed to whiptail msgbox option.
This fails with other "sudo ... " commands, and only with "sudo .. commands.
My guess is there are non printing characters in the output text causing this issue.
sudo iwlist wlan0 scan
wlan0 Interface doesn't support scanning : Network is down
whiptail --title 'Command sudo iwlist wlan0 scan output 1400' - -separate-output --scrolltext --msgbox '' 17 80 10
io-redirection
asked Sep 10 at 22:10
Jan Hus
1466
add a comment |Â
up vote
1
down vote
favorite
I am enclosing bash -x output which shows that the command "sudo iwlist wlan0 scan" was executed and returned expected text to terminal .
The issue is - this text was not passed to whiptail msgbox option.
This fails with other "sudo ... " commands, and only with "sudo .. commands.
My guess is there are non printing characters in the output text causing this issue.
sudo iwlist wlan0 scan
wlan0 Interface doesn't support scanning : Network is down
whiptail --title 'Command sudo iwlist wlan0 scan output 1400' - -separate-output --scrolltext --msgbox '' 17 80 10
io-redirection
asked Sep 10 at 22:10
Jan Hus
1466
I like to totally rebuild my question - is that OK?
– Jan Hus
Sep 12 at 15:42
add a comment |Â
up vote
1
down vote
favorite
up vote
1
down vote
favorite
I am enclosing bash -x output which shows that the command "sudo iwlist wlan0 scan" was executed and returned expected text to terminal .
The issue is - this text was not passed to whiptail msgbox option.
This fails with other "sudo ... " commands, and only with "sudo .. commands.
My guess is there are non printing characters in the output text causing this issue.
sudo iwlist wlan0 scan
wlan0 Interface doesn't support scanning : Network is down
whiptail --title 'Command sudo iwlist wlan0 scan output 1400' - -separate-output --scrolltext --msgbox '' 17 80 10
io-redirection
asked Sep 10 at 22:10
Jan Hus
1466
I am enclosing bash -x output which shows that the command "sudo iwlist wlan0 scan" was executed and returned expected text to terminal .
The issue is - this text was not passed to whiptail msgbox option.
This fails with other "sudo ... " commands, and only with "sudo .. commands.
My guess is there are non printing characters in the output text causing this issue.
sudo iwlist wlan0 scan
wlan0 Interface doesn't support scanning : Network is down
whiptail --title 'Command sudo iwlist wlan0 scan output 1400' - -separate-output --scrolltext --msgbox '' 17 80 10
io-redirection
io-redirection
asked Sep 10 at 22:10
Jan Hus
1466
asked Sep 10 at 22:10
Jan Hus
1466
edited Sep 25 at 21:19
asked Sep 10 at 22:10
Jan Hus
1466
asked Sep 10 at 22:10
Jan Hus
1466
asked Sep 10 at 22:10
Jan Hus
1466
1466
I like to totally rebuild my question - is that OK?
– Jan Hus
Sep 12 at 15:42
add a comment |Â
I like to totally rebuild my question - is that OK?
– Jan Hus
Sep 12 at 15:42
I like to totally rebuild my question - is that OK?
– Jan Hus
Sep 12 at 15:42
I like to totally rebuild my question - is that OK?
– Jan Hus
Sep 12 at 15:42
add a comment |Â
1 Answer
1
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oldest
votes
up vote
0
down vote
accepted
Whenever you are not sure, try redirecting the stdout then stderr to /dev/null.
For example, with lsusb -h > /dev/null you can still see the output, whereas with lsusb -h 2> /dev/null there's not output - therefore, the output of the help goes to stderr.
If you want to redirect stderr to stdout:lsusb -h 2>&1
It's not obvious (at first) but what this command does is redirect stderr (file descriptor #2) to stdout (file descriptor #1).
answered Sep 10 at 22:23
pi0tr
1652
lsusb -h > /dev/null you can still see the output yes I do in terminal and it locks it up I need to see it on screen "stdout"
– Jan Hus
Sep 11 at 16:44
Actually I see all on terminal, the variable is passed to whiptail which I need to redirect.
– Jan Hus
Sep 11 at 16:47
Well, without any additional information from your part, it's going to be hard to help you! ;) The example below works, but I don't know how well it would fit into your script:whiptail --msgbox "$(lsusb 2>&1)" 20 80
– pi0tr
Sep 13 at 13:05
What other info do you need?
– Jan Hus
Sep 13 at 14:16
Well, I have no idea what your script does, or how it works. This makes it hard to be relevant. From what I understand, you want some variable to hold both the stdout and stderr output of thelsudbcommand. For example:var=$(lsusb -h 2>&1)The variablevarwill hold both stdout and stderr; you can then use it with whiptail:whiptail --msgbox "$var" 20 80
– pi0tr
Sep 13 at 16:54
 |Â
show 1 more comment
1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
up vote
0
down vote
accepted
Whenever you are not sure, try redirecting the stdout then stderr to /dev/null.
For example, with lsusb -h > /dev/null you can still see the output, whereas with lsusb -h 2> /dev/null there's not output - therefore, the output of the help goes to stderr.
If you want to redirect stderr to stdout:lsusb -h 2>&1
It's not obvious (at first) but what this command does is redirect stderr (file descriptor #2) to stdout (file descriptor #1).
answered Sep 10 at 22:23
pi0tr
1652
lsusb -h > /dev/null you can still see the output yes I do in terminal and it locks it up I need to see it on screen "stdout"
– Jan Hus
Sep 11 at 16:44
Actually I see all on terminal, the variable is passed to whiptail which I need to redirect.
– Jan Hus
Sep 11 at 16:47
Well, without any additional information from your part, it's going to be hard to help you! ;) The example below works, but I don't know how well it would fit into your script:whiptail --msgbox "$(lsusb 2>&1)" 20 80
– pi0tr
Sep 13 at 13:05
What other info do you need?
– Jan Hus
Sep 13 at 14:16
Well, I have no idea what your script does, or how it works. This makes it hard to be relevant. From what I understand, you want some variable to hold both the stdout and stderr output of thelsudbcommand. For example:var=$(lsusb -h 2>&1)The variablevarwill hold both stdout and stderr; you can then use it with whiptail:whiptail --msgbox "$var" 20 80
– pi0tr
Sep 13 at 16:54
 |Â
show 1 more comment
up vote
0
down vote
accepted
Whenever you are not sure, try redirecting the stdout then stderr to /dev/null.
For example, with lsusb -h > /dev/null you can still see the output, whereas with lsusb -h 2> /dev/null there's not output - therefore, the output of the help goes to stderr.
If you want to redirect stderr to stdout:lsusb -h 2>&1
It's not obvious (at first) but what this command does is redirect stderr (file descriptor #2) to stdout (file descriptor #1).
answered Sep 10 at 22:23
pi0tr
1652
lsusb -h > /dev/null you can still see the output yes I do in terminal and it locks it up I need to see it on screen "stdout"
– Jan Hus
Sep 11 at 16:44
Actually I see all on terminal, the variable is passed to whiptail which I need to redirect.
– Jan Hus
Sep 11 at 16:47
Well, without any additional information from your part, it's going to be hard to help you! ;) The example below works, but I don't know how well it would fit into your script:whiptail --msgbox "$(lsusb 2>&1)" 20 80
– pi0tr
Sep 13 at 13:05
What other info do you need?
– Jan Hus
Sep 13 at 14:16
Well, I have no idea what your script does, or how it works. This makes it hard to be relevant. From what I understand, you want some variable to hold both the stdout and stderr output of thelsudbcommand. For example:var=$(lsusb -h 2>&1)The variablevarwill hold both stdout and stderr; you can then use it with whiptail:whiptail --msgbox "$var" 20 80
– pi0tr
Sep 13 at 16:54
 |Â
show 1 more comment
up vote
0
down vote
accepted
up vote
0
down vote
accepted
Whenever you are not sure, try redirecting the stdout then stderr to /dev/null.
For example, with lsusb -h > /dev/null you can still see the output, whereas with lsusb -h 2> /dev/null there's not output - therefore, the output of the help goes to stderr.
If you want to redirect stderr to stdout:lsusb -h 2>&1
It's not obvious (at first) but what this command does is redirect stderr (file descriptor #2) to stdout (file descriptor #1).
answered Sep 10 at 22:23
pi0tr
1652
Whenever you are not sure, try redirecting the stdout then stderr to /dev/null.
For example, with lsusb -h > /dev/null you can still see the output, whereas with lsusb -h 2> /dev/null there's not output - therefore, the output of the help goes to stderr.
If you want to redirect stderr to stdout:lsusb -h 2>&1
It's not obvious (at first) but what this command does is redirect stderr (file descriptor #2) to stdout (file descriptor #1).
answered Sep 10 at 22:23
pi0tr
1652
answered Sep 10 at 22:23
pi0tr
1652
answered Sep 10 at 22:23
pi0tr
1652
answered Sep 10 at 22:23
pi0tr
1652
1652
lsusb -h > /dev/null you can still see the output yes I do in terminal and it locks it up I need to see it on screen "stdout"
– Jan Hus
Sep 11 at 16:44
Actually I see all on terminal, the variable is passed to whiptail which I need to redirect.
– Jan Hus
Sep 11 at 16:47
Well, without any additional information from your part, it's going to be hard to help you! ;) The example below works, but I don't know how well it would fit into your script:whiptail --msgbox "$(lsusb 2>&1)" 20 80
– pi0tr
Sep 13 at 13:05
What other info do you need?
– Jan Hus
Sep 13 at 14:16
Well, I have no idea what your script does, or how it works. This makes it hard to be relevant. From what I understand, you want some variable to hold both the stdout and stderr output of thelsudbcommand. For example:var=$(lsusb -h 2>&1)The variablevarwill hold both stdout and stderr; you can then use it with whiptail:whiptail --msgbox "$var" 20 80
– pi0tr
Sep 13 at 16:54
 |Â
show 1 more comment
lsusb -h > /dev/null you can still see the output yes I do in terminal and it locks it up I need to see it on screen "stdout"
– Jan Hus
Sep 11 at 16:44
Actually I see all on terminal, the variable is passed to whiptail which I need to redirect.
– Jan Hus
Sep 11 at 16:47
Well, without any additional information from your part, it's going to be hard to help you! ;) The example below works, but I don't know how well it would fit into your script:whiptail --msgbox "$(lsusb 2>&1)" 20 80
– pi0tr
Sep 13 at 13:05
What other info do you need?
– Jan Hus
Sep 13 at 14:16
Well, I have no idea what your script does, or how it works. This makes it hard to be relevant. From what I understand, you want some variable to hold both the stdout and stderr output of thelsudbcommand. For example:var=$(lsusb -h 2>&1)The variablevarwill hold both stdout and stderr; you can then use it with whiptail:whiptail --msgbox "$var" 20 80
– pi0tr
Sep 13 at 16:54
lsusb -h > /dev/null you can still see the output yes I do in terminal and it locks it up I need to see it on screen "stdout"
– Jan Hus
Sep 11 at 16:44
lsusb -h > /dev/null you can still see the output yes I do in terminal and it locks it up I need to see it on screen "stdout"
– Jan Hus
Sep 11 at 16:44
Actually I see all on terminal, the variable is passed to whiptail which I need to redirect.
– Jan Hus
Sep 11 at 16:47
Actually I see all on terminal, the variable is passed to whiptail which I need to redirect.
– Jan Hus
Sep 11 at 16:47
Well, without any additional information from your part, it's going to be hard to help you! ;) The example below works, but I don't know how well it would fit into your script:
whiptail --msgbox "$(lsusb 2>&1)" 20 80– pi0tr
Sep 13 at 13:05
Well, without any additional information from your part, it's going to be hard to help you! ;) The example below works, but I don't know how well it would fit into your script:
whiptail --msgbox "$(lsusb 2>&1)" 20 80– pi0tr
Sep 13 at 13:05
What other info do you need?
– Jan Hus
Sep 13 at 14:16
What other info do you need?
– Jan Hus
Sep 13 at 14:16
Well, I have no idea what your script does, or how it works. This makes it hard to be relevant. From what I understand, you want some variable to hold both the stdout and stderr output of the
lsudb command. For example: var=$(lsusb -h 2>&1) The variable var will hold both stdout and stderr; you can then use it with whiptail: whiptail --msgbox "$var" 20 80– pi0tr
Sep 13 at 16:54
Well, I have no idea what your script does, or how it works. This makes it hard to be relevant. From what I understand, you want some variable to hold both the stdout and stderr output of the
lsudb command. For example: var=$(lsusb -h 2>&1) The variable var will hold both stdout and stderr; you can then use it with whiptail: whiptail --msgbox "$var" 20 80– pi0tr
Sep 13 at 16:54
 |Â
show 1 more comment
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I like to totally rebuild my question - is that OK?
– Jan Hus
Sep 12 at 15:42