return
instead of break
.foo() {
if [[ -z $1 ]]
then
break
fi
echo "Hello $1"
}
foo() {
if [[ -z $1 ]]
then
return 1
fi
echo "Hello $1"
}
break
or continue
are used to abort or
continue a loop, and are not the right way to exit a function. Use
return
instead.
The break
or continue
may be intended for a
loop that calls the function:
# Rarely valid
foo() { break; echo $?; }
while true; do foo; done
This is undefined behavior in POSIX sh. Different shells do different things.
When the function is called from a loop:
ksh
keeps going and $?
is 0.bash
version 4.4+ prints an error "break: only
meaningful in a `for', `while', or `until' loop", the function keeps
going, and $?
is 0.bash
versions before 4.4, will return from the
function, break the loop calling the function, or exit a subshell if
there's one in between.dash
, BusyBox ash
: like above.When the function is not called from a loop:
bash
versions print an error "break: only
meaningful in a `for', `while', or `until' loop", the function keeps
going, and $?
is 0.ksh
, dash
and ash
silently
keep going and $?
is 0.Due to the many different implementations, many of which are not
helpful, it's recommended to use proper flow control. A typical solution
is making sure the function return
s success/failure, and
calling myfunction || break
in the loop.
ShellCheck is a static analysis tool for shell scripts. This page is part of its documentation.