Is it possible to “coax” arbitrary core *nix utilities into returning a non-zero exit status even when...
This is my first time posting to StackExchange. If there is an issue with my question please let me know so that I can correct it. :) I have done quite a bit of searching on the topic, as well as attempted some things on my own, to no avail.
Background
I am running bash scripts and executing bash commands on remote systems using Connectwise Automate (formerly LabTech). These systems are both Linux and MacOS. Connectwise Automate (CWA) has some peculiar behavior with regards to *nix systems, wherein if a command or expression exits with a status code of 0 all output, regardless of stream (stdout or stderr), is replaced with the word "OK". When a non-0 exit status is returned the output is properly displayed in the CWA's remote terminal and script output. I have not received definitive confirmation that the output replacement behavior is based on exit code, however I believe it to be highly likely.
For a simplistic example, echo "Test" returns OK, whereas ls ./no/such/directory yields the appropriate exception. This is a long-standing issue with CWA and working with the vendor yields no workarounds or positive results without piping the command output to a file on disk and reading that file with a function particular to CWA. That yields inconsistent results, however, as often the command output that gets written to file is simply OK.
What I've tried
I've found and attempted many possible solutions. I found this question, specifically geared towards less, and was reliant on less's -K argument. I attempted to adapt part of the solution with no success invoking bash -c and trap, though my implementation could have been incorrect. I also attempted something along the lines of echo "Test" && false, which returns OK, likely (in my mind) due to the first command returning with an exit code of 0 before evaluating false.
Question restated
Is it possible to "coax" (so to speak) arbitrary utilities, particularly when invoked via bash or sh, into returning with an exit status of my choosing, or otherwise any non-0 exit status, and still have a given utility's output hit stdout/stderr? Thanks in advance for your time!
bash shell exit-code
asked Feb 6 at 0:47
Scott CarlowScott Carlow
11
|
show 5 more comments
This is my first time posting to StackExchange. If there is an issue with my question please let me know so that I can correct it. :) I have done quite a bit of searching on the topic, as well as attempted some things on my own, to no avail.
Background
I am running bash scripts and executing bash commands on remote systems using Connectwise Automate (formerly LabTech). These systems are both Linux and MacOS. Connectwise Automate (CWA) has some peculiar behavior with regards to *nix systems, wherein if a command or expression exits with a status code of 0 all output, regardless of stream (stdout or stderr), is replaced with the word "OK". When a non-0 exit status is returned the output is properly displayed in the CWA's remote terminal and script output. I have not received definitive confirmation that the output replacement behavior is based on exit code, however I believe it to be highly likely.
For a simplistic example, echo "Test" returns OK, whereas ls ./no/such/directory yields the appropriate exception. This is a long-standing issue with CWA and working with the vendor yields no workarounds or positive results without piping the command output to a file on disk and reading that file with a function particular to CWA. That yields inconsistent results, however, as often the command output that gets written to file is simply OK.
What I've tried
I've found and attempted many possible solutions. I found this question, specifically geared towards less, and was reliant on less's -K argument. I attempted to adapt part of the solution with no success invoking bash -c and trap, though my implementation could have been incorrect. I also attempted something along the lines of echo "Test" && false, which returns OK, likely (in my mind) due to the first command returning with an exit code of 0 before evaluating false.
Question restated
Is it possible to "coax" (so to speak) arbitrary utilities, particularly when invoked via bash or sh, into returning with an exit status of my choosing, or otherwise any non-0 exit status, and still have a given utility's output hit stdout/stderr? Thanks in advance for your time!
bash shell exit-code
asked Feb 6 at 0:47
Scott CarlowScott Carlow
11
2
You could do(command_you_want && exit 1)which will return an exit code of 1 if the command is successful, and leave it unchanged if it fails.
– Stephen Harris
Feb 6 at 0:56
1
Sinceecho "Test" && falsecertainly does exit with a non-zero return code, something else about how the commands are running is getting in the way of achieving what you want (and it may not be what you think). How does it run the commands? Can you see what is actually executed? Isbash -c 'echo "Test" && falsedifferent, or is that what you already tried?
– Michael Homer
Feb 6 at 1:33
@MichaelHomer I have already triedbash -c 'echo "Test" && false'to no avail. Correct me if I'm wrong, but my understanding of how the above command would work is thebash -c 'echo "test"portion will return with an exit status of 0 before proceeding. The flow control operator&&actually relies on the the command to the left of it to return successful before proceeding. Do I have that right?
– Scott Carlow
Feb 6 at 18:42
@StephenHarris Unfortunately,echostill returns with an exit code of 0 before moving on toexit 1. With a simplistic test of(echo "Test" && echo $? && exit 1)I get the outputTest 0then it exits and sets$?to 1.
– Scott Carlow
Feb 6 at 18:46
echo test && false(in every permutation posted so far) unequivocally exits 1. I don't know how this tool launches its programs, or how it decides what the result was, but something is not happening in the way you think it is.
– Michael Homer
Feb 6 at 19:07
|
show 5 more comments
This is my first time posting to StackExchange. If there is an issue with my question please let me know so that I can correct it. :) I have done quite a bit of searching on the topic, as well as attempted some things on my own, to no avail.
Background
I am running bash scripts and executing bash commands on remote systems using Connectwise Automate (formerly LabTech). These systems are both Linux and MacOS. Connectwise Automate (CWA) has some peculiar behavior with regards to *nix systems, wherein if a command or expression exits with a status code of 0 all output, regardless of stream (stdout or stderr), is replaced with the word "OK". When a non-0 exit status is returned the output is properly displayed in the CWA's remote terminal and script output. I have not received definitive confirmation that the output replacement behavior is based on exit code, however I believe it to be highly likely.
For a simplistic example, echo "Test" returns OK, whereas ls ./no/such/directory yields the appropriate exception. This is a long-standing issue with CWA and working with the vendor yields no workarounds or positive results without piping the command output to a file on disk and reading that file with a function particular to CWA. That yields inconsistent results, however, as often the command output that gets written to file is simply OK.
What I've tried
I've found and attempted many possible solutions. I found this question, specifically geared towards less, and was reliant on less's -K argument. I attempted to adapt part of the solution with no success invoking bash -c and trap, though my implementation could have been incorrect. I also attempted something along the lines of echo "Test" && false, which returns OK, likely (in my mind) due to the first command returning with an exit code of 0 before evaluating false.
Question restated
Is it possible to "coax" (so to speak) arbitrary utilities, particularly when invoked via bash or sh, into returning with an exit status of my choosing, or otherwise any non-0 exit status, and still have a given utility's output hit stdout/stderr? Thanks in advance for your time!
bash shell exit-code
asked Feb 6 at 0:47
Scott CarlowScott Carlow
11
This is my first time posting to StackExchange. If there is an issue with my question please let me know so that I can correct it. :) I have done quite a bit of searching on the topic, as well as attempted some things on my own, to no avail.
Background
I am running bash scripts and executing bash commands on remote systems using Connectwise Automate (formerly LabTech). These systems are both Linux and MacOS. Connectwise Automate (CWA) has some peculiar behavior with regards to *nix systems, wherein if a command or expression exits with a status code of 0 all output, regardless of stream (stdout or stderr), is replaced with the word "OK". When a non-0 exit status is returned the output is properly displayed in the CWA's remote terminal and script output. I have not received definitive confirmation that the output replacement behavior is based on exit code, however I believe it to be highly likely.
For a simplistic example, echo "Test" returns OK, whereas ls ./no/such/directory yields the appropriate exception. This is a long-standing issue with CWA and working with the vendor yields no workarounds or positive results without piping the command output to a file on disk and reading that file with a function particular to CWA. That yields inconsistent results, however, as often the command output that gets written to file is simply OK.
What I've tried
I've found and attempted many possible solutions. I found this question, specifically geared towards less, and was reliant on less's -K argument. I attempted to adapt part of the solution with no success invoking bash -c and trap, though my implementation could have been incorrect. I also attempted something along the lines of echo "Test" && false, which returns OK, likely (in my mind) due to the first command returning with an exit code of 0 before evaluating false.
Question restated
Is it possible to "coax" (so to speak) arbitrary utilities, particularly when invoked via bash or sh, into returning with an exit status of my choosing, or otherwise any non-0 exit status, and still have a given utility's output hit stdout/stderr? Thanks in advance for your time!
bash shell exit-code
bash shell exit-code
asked Feb 6 at 0:47
Scott CarlowScott Carlow
11
asked Feb 6 at 0:47
Scott CarlowScott Carlow
11
edited Feb 6 at 0:53
Scott Carlow
asked Feb 6 at 0:47
Scott CarlowScott Carlow
11
asked Feb 6 at 0:47
Scott CarlowScott Carlow
11
asked Feb 6 at 0:47
Scott CarlowScott Carlow
11
11
2
You could do(command_you_want && exit 1)which will return an exit code of 1 if the command is successful, and leave it unchanged if it fails.
– Stephen Harris
Feb 6 at 0:56
1
Sinceecho "Test" && falsecertainly does exit with a non-zero return code, something else about how the commands are running is getting in the way of achieving what you want (and it may not be what you think). How does it run the commands? Can you see what is actually executed? Isbash -c 'echo "Test" && falsedifferent, or is that what you already tried?
– Michael Homer
Feb 6 at 1:33
@MichaelHomer I have already triedbash -c 'echo "Test" && false'to no avail. Correct me if I'm wrong, but my understanding of how the above command would work is thebash -c 'echo "test"portion will return with an exit status of 0 before proceeding. The flow control operator&&actually relies on the the command to the left of it to return successful before proceeding. Do I have that right?
– Scott Carlow
Feb 6 at 18:42
@StephenHarris Unfortunately,echostill returns with an exit code of 0 before moving on toexit 1. With a simplistic test of(echo "Test" && echo $? && exit 1)I get the outputTest 0then it exits and sets$?to 1.
– Scott Carlow
Feb 6 at 18:46
echo test && false(in every permutation posted so far) unequivocally exits 1. I don't know how this tool launches its programs, or how it decides what the result was, but something is not happening in the way you think it is.
– Michael Homer
Feb 6 at 19:07
|
show 5 more comments
2
You could do(command_you_want && exit 1)which will return an exit code of 1 if the command is successful, and leave it unchanged if it fails.
– Stephen Harris
Feb 6 at 0:56
1
Sinceecho "Test" && falsecertainly does exit with a non-zero return code, something else about how the commands are running is getting in the way of achieving what you want (and it may not be what you think). How does it run the commands? Can you see what is actually executed? Isbash -c 'echo "Test" && falsedifferent, or is that what you already tried?
– Michael Homer
Feb 6 at 1:33
@MichaelHomer I have already triedbash -c 'echo "Test" && false'to no avail. Correct me if I'm wrong, but my understanding of how the above command would work is thebash -c 'echo "test"portion will return with an exit status of 0 before proceeding. The flow control operator&&actually relies on the the command to the left of it to return successful before proceeding. Do I have that right?
– Scott Carlow
Feb 6 at 18:42
@StephenHarris Unfortunately,echostill returns with an exit code of 0 before moving on toexit 1. With a simplistic test of(echo "Test" && echo $? && exit 1)I get the outputTest 0then it exits and sets$?to 1.
– Scott Carlow
Feb 6 at 18:46
echo test && false(in every permutation posted so far) unequivocally exits 1. I don't know how this tool launches its programs, or how it decides what the result was, but something is not happening in the way you think it is.
– Michael Homer
Feb 6 at 19:07
2
2
You could do
(command_you_want && exit 1) which will return an exit code of 1 if the command is successful, and leave it unchanged if it fails.– Stephen Harris
Feb 6 at 0:56
You could do
(command_you_want && exit 1) which will return an exit code of 1 if the command is successful, and leave it unchanged if it fails.– Stephen Harris
Feb 6 at 0:56
1
1
Since
echo "Test" && false certainly does exit with a non-zero return code, something else about how the commands are running is getting in the way of achieving what you want (and it may not be what you think). How does it run the commands? Can you see what is actually executed? Is bash -c 'echo "Test" && false different, or is that what you already tried?– Michael Homer
Feb 6 at 1:33
Since
echo "Test" && false certainly does exit with a non-zero return code, something else about how the commands are running is getting in the way of achieving what you want (and it may not be what you think). How does it run the commands? Can you see what is actually executed? Is bash -c 'echo "Test" && false different, or is that what you already tried?– Michael Homer
Feb 6 at 1:33
@MichaelHomer I have already tried
bash -c 'echo "Test" && false' to no avail. Correct me if I'm wrong, but my understanding of how the above command would work is the bash -c 'echo "test" portion will return with an exit status of 0 before proceeding. The flow control operator && actually relies on the the command to the left of it to return successful before proceeding. Do I have that right?– Scott Carlow
Feb 6 at 18:42
@MichaelHomer I have already tried
bash -c 'echo "Test" && false' to no avail. Correct me if I'm wrong, but my understanding of how the above command would work is the bash -c 'echo "test" portion will return with an exit status of 0 before proceeding. The flow control operator && actually relies on the the command to the left of it to return successful before proceeding. Do I have that right?– Scott Carlow
Feb 6 at 18:42
@StephenHarris Unfortunately,
echo still returns with an exit code of 0 before moving on to exit 1. With a simplistic test of (echo "Test" && echo $? && exit 1) I get the output Test 0 then it exits and sets $? to 1.– Scott Carlow
Feb 6 at 18:46
@StephenHarris Unfortunately,
echo still returns with an exit code of 0 before moving on to exit 1. With a simplistic test of (echo "Test" && echo $? && exit 1) I get the output Test 0 then it exits and sets $? to 1.– Scott Carlow
Feb 6 at 18:46
echo test && false (in every permutation posted so far) unequivocally exits 1. I don't know how this tool launches its programs, or how it decides what the result was, but something is not happening in the way you think it is.– Michael Homer
Feb 6 at 19:07
echo test && false (in every permutation posted so far) unequivocally exits 1. I don't know how this tool launches its programs, or how it decides what the result was, but something is not happening in the way you think it is.– Michael Homer
Feb 6 at 19:07
|
show 5 more comments
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2
You could do
(command_you_want && exit 1)which will return an exit code of 1 if the command is successful, and leave it unchanged if it fails.– Stephen Harris
Feb 6 at 0:56
1
Since
echo "Test" && falsecertainly does exit with a non-zero return code, something else about how the commands are running is getting in the way of achieving what you want (and it may not be what you think). How does it run the commands? Can you see what is actually executed? Isbash -c 'echo "Test" && falsedifferent, or is that what you already tried?– Michael Homer
Feb 6 at 1:33
@MichaelHomer I have already tried
bash -c 'echo "Test" && false'to no avail. Correct me if I'm wrong, but my understanding of how the above command would work is thebash -c 'echo "test"portion will return with an exit status of 0 before proceeding. The flow control operator&&actually relies on the the command to the left of it to return successful before proceeding. Do I have that right?– Scott Carlow
Feb 6 at 18:42
@StephenHarris Unfortunately,
echostill returns with an exit code of 0 before moving on toexit 1. With a simplistic test of(echo "Test" && echo $? && exit 1)I get the outputTest 0then it exits and sets$?to 1.– Scott Carlow
Feb 6 at 18:46
echo test && false(in every permutation posted so far) unequivocally exits 1. I don't know how this tool launches its programs, or how it decides what the result was, but something is not happening in the way you think it is.– Michael Homer
Feb 6 at 19:07