问题
I want to know whether any commands in a bash script exited with a non-zero status.
I want something similar to set -e
functionality, except that I don't want it to exit when a command exits with a non-zero status. I want it to run the whole script, and then I want to know that either:
a) all commands exited with exit status 0
-or-
b) one or more commands exited with a non-zero status
e.g., given the following:
#!/bin/bash
command1 # exits with status 1
command2 # exits with status 0
command3 # exits with status 0
I want all three commands to run. After running the script, I want an indication that at least one of the commands exited with a non-zero status.
回答1:
Set a trap on ERR:
#!/bin/bash
err=0
trap 'err=1' ERR
command1
command2
command3
test $err = 0 # Return non-zero if any command failed
You might even throw in a little introspection to get data about where the error occurred:
#!/bin/bash
for i in 1 2 3; do
eval "command$i() { echo command$i; test $i != 2; }"
done
err=0
report() {
err=1
echo -n "error at line ${BASH_LINENO[0]}, in call to "
sed -n ${BASH_LINENO[0]}p $0
} >&2
trap report ERR
command1
command2
command3
exit $err
回答2:
You could try to do something with a trap for the DEBUG
pseudosignal, such as
trap '(( $? && ++errcount ))' DEBUG
The DEBUG
trap is executed "before every simple command, for
command, case
command, select
command, every arithmetic for
command, and before the first command executes in a shell function" (quote from manual).
So if you add this trap and as the last command something to print the error count, you get the proper value:
#!/bin/bash
trap '(( $? && ++errcount ))' DEBUG
true
false
true
echo "Errors: $errcount"
returns Errors: 1
and
#!/bin/bash
trap '(( $? && ++errcount ))' DEBUG
true
false
true
false
echo "Errors: $errcount"
prints Errors: 2
. Beware that that last statement is actually required to account for the second false
because the trap is executed before the commands, so the exit status for the second false
is only checked when the trap for the echo
line is executed.
回答3:
I am not sure if there is a ready-made solution for your requirement. I would write a function like this:
function run_cmd_with_check() {
"$@"
[[ $? -ne 0 ]] && ((non_zero++))
}
Then, use the function to run all the commands that need tracking:
run_cmd_with_check command1
run_cmd_with_check command2
run_cmd_with_check command3
printf "$non_zero commands exited with non-zero exit code\n"
If required, the function can be enhanced to store all failed commands in an array which can be printed out at the end.
You may want to take a look at this post for more info: Error handling in Bash
回答4:
You have the magic variable $?
available in bash which tells the exit code of last command:
#!/bin/bash
command1 # exits with status 1
C1_output=$? # will be 1
command2 # exits with status 0
C2_output=$? # will be 0
command3 # exits with status 0
C3_output=$? # will be 0
回答5:
For each command you could do this:
if ! Command1 ; then an_error=1; fi
And repeat this for all commands
At the end an_error will be 1 if any of them failed.
If you want a count of failures set an_error to 0 at the beginning and do $((an_error++)). Instead of an_error=1
回答6:
You could place your list of commands into an array and then loop over the commands. Any that return an error code your keep the results for later viewing.
declare -A results
commands=("your" "commands")
for cmd in "${commands[@]}"; do
out=$($cmd 2>&1)
[[ $? -eq 0 ]] || results[$cmd]="$out"
done
Then to see any non zero exit codes:
for cmd in "${!results[@]}"; do echo "$cmd = ${results[$cmd]}"; done
If the length of results
is 0, there were no errors on your list of commands.
This requires Bash 4+ (for the associative array)
回答7:
You can use the DEBUG
trap like:
trap 'code+=$?' DEBUG
code=0
# run commands here normally
exit $code
来源:https://stackoverflow.com/questions/42218009/how-to-tell-if-any-command-in-bash-script-failed-non-zero-exit-status