I'm trying to use a break statement in a for loop, but since I'm also using strict subs in my Perl code, I'm getting an error saying:
Bareword "break" not allowed while "strict subs" in use at ./final.pl line 154.
Is there a workaround for this (besides disabling strict subs)?
My code is formatted as follows:
for my $entry (@array){
if ($string eq "text"){
break;
}
}
On a large iteration I like using interrupts. Just press Ctrl + C to quit:
my $exitflag = 0;
$SIG{INT} = sub { $exitflag=1 };
while(!$exitflag) {
# Do your stuff
}
For Perl one-liners with implicit loops (using -n or -p command line options), use last or last LINE to break out of the loop that iterates over input records. For example, these simple examples all print the first 2 lines of the input:
echo 1 2 3 4 | xargs -n1 | perl -ne 'last if $. == 3; print;'
echo 1 2 3 4 | xargs -n1 | perl -ne 'last LINE if $. == 3; print;'
echo 1 2 3 4 | xargs -n1 | perl -pe 'last if $. == 3;'
echo 1 2 3 4 | xargs -n1 | perl -pe 'last LINE if $. == 3;'
All print:
1
2
The perl one-liners use these command line flags:
-e : tells Perl to look for code in-line, instead of in a file.
-n : loop over the input one line at a time, assigning it to $_ by default.
-p : same as -n, also add print after each loop iteration over the input.
SEE ALSO:
last docs
last, next, redo, continue - an illustrated example
perlrun: command line switches docs
More examples of last in Perl one-liners:
Break one liner command line script after first match
Print the first N lines of a huge file
Simply last would work here:
for my $entry (@array){
if ($string eq "text"){
last;
}
}
If you have nested loops, then last will exit from the innermost loop. Use labels in this case:
LBL_SCORE: {
for my $entry1 (@array1) {
for my $entry2 (@array2) {
if ($entry1 eq $entry2) { # Or any condition
last LBL_SCORE;
}
}
}
}
Given a last statement will make the compiler to come out from both the loops. The same can be done in any number of loops, and labels can be fixed anywhere.
On a large iteration I like using interrupts. Just press Ctrl + C to quit:
my $exitflag = 0;
$SIG{INT} = sub { $exitflag=1 };
while(!$exitflag) {
# Do your stuff
}
Additional data (in case you have more questions):
FOO: {
for my $i ( @listone ){
for my $j ( @listtwo ){
if ( cond( $i,$j ) ){
last FOO; # --->
# |
} # |
} # |
} # |
} # <-------------------------------
Additional data (in case you have more questions):
FOO: {
for my $i ( @listone ){
for my $j ( @listtwo ){
if ( cond( $i,$j ) ){
last FOO; # --->
# |
} # |
} # |
} # |
} # <-------------------------------
Simply last would work here:
for my $entry (@array){
if ($string eq "text"){
last;
}
}
If you have nested loops, then last will exit from the innermost loop. Use labels in this case:
LBL_SCORE: {
for my $entry1 (@array1) {
for my $entry2 (@array2) {
if ($entry1 eq $entry2) { # Or any condition
last LBL_SCORE;
}
}
}
}
Given a last statement will make the compiler to come out from both the loops. The same can be done in any number of loops, and labels can be fixed anywhere.
Additional data (in case you have more questions):
FOO: {
for my $i ( @listone ){
for my $j ( @listtwo ){
if ( cond( $i,$j ) ){
last FOO; # --->
# |
} # |
} # |
} # |
} # <-------------------------------
Source: Stackoverflow.com