>perl -e '$_ = q(t b[\)sizeof];); s/(t?(\w)(?:\s(\w))?\s(\w)(\[([^\]]+)\]))/eval $1/e'
Bareword found where operator expected at (eval 1) line 1, near ")sizeof"
(Missing operator before sizeof?)
This is legal Perl, then why the error message? I have the latest Perl.
This is an SSCCE ; any one character less and the error message does not appear.
The Perl code is valid, but you are trying to eval a string which is not valid Perl code. When I run this code and swap eval for print, it prints the string:
t b[)sizeof]
Now if I try and run this as Perl code I get:
> perl -we't b[)sizeof]'
Bareword found where operator expected at -e line 1, near ")sizeof"
(Missing operator before sizeof?)
Unquoted string "sizeof" may clash with future reserved word at -e line 1.
syntax error at -e line 1, near "[)"
Execution of -e aborted due to compilation errors.
(You should always use warnings -w, even with one-liners)
This code does exactly what your evaluation is trying to do: It's trying to run that string as Perl code, and it fails because that string is not valid Perl code.
Also you should be careful when using eval, as it can do unexpected and catastrophical things to your computer. Usually, this kind of double evaluation is written using two of the /e modifiers, e.g.:
s/.../.../ee
Which is a bit more convenient than
s/.../eval .../e
Related
How can I run this command in my Jenkins file?
sh "perl -p -e 's/\$\{([^}]+)\}/defined $ENV{$1} ? $ENV{$1} : $&/eg; s/\$\{([^}]+)\}//eg' .env"
I tried everything.
Like so:
sh """
perl -p -e 's/\$\{([^}]+)\}/defined $ENV{$1} ? $ENV{$1} : $&/eg; s/\$\{([^}]+)\}//eg' .env
"""
Or escaping the backslahes.
But I keep getting the error:
WorkflowScript: 13: unexpected char: '\' # line 13, column 23.
Depending on how this command is run, the string interpolation issues can be awful to predict. Is the double quoted string interpolated by sh? Does the backslash in front of $ mean that it is escaped from sh, but not from Perl interpolation? When I ran a test string in pastebin, it simply removed the $ENV{$1}.
I'm sure there's a way to do it the hard way (this way), but an easy way is to just write the Perl code in a file instead, and run the file.
I would write your regexes like this, in a separate file, say foo.pl:
s|\${([^}]+)}|$ENV{$1} // $&|eg;
s/\${([^}]+)}//g;
Using the logical defined-or operator // is slightly prettier than using the ternary operator. We change delimiter on the substitution operator to facilitate that.
I removed unused e modifier on second substitution.
You should note that all strings that match the regex ${....} will be removed from the input by the second substitution. So the fact that you attempt to put them back with the first substitution with $& is quite meaningless. Moreover using $& carries a notable performance reduction. Assuming that is a mistake from your side, the code can be shortened to:
s/\${([^}]+)}/$ENV{$1}/g;
Note that now you can also skip the dangerous eval modifier /e.
If you run it without warnings, which you do in your original code, you will not notice the undefined values in the %ENV hash, it will just return the empty string -- i.e. remove undefined values.
This code can now be run by your other script without interpolation issues:
sh "perl -p foo.pl .env"
Just remove the -e switch since you are no longer providing command line code.
Has anyone tried this code on cygwin?
I get these errors:
Can't find string terminator "'" anywhere before EOF at -e line 1.
Use of uninitialized value in pattern match (m//) at ./dos_it.pl line 506.
Use of uninitialized value $shellpath in rindex at ./dos_it.pl line 586.
Use of uninitialized value $shellpath in substr at ./dos_it.pl line 586.
Use of uninitialized value $pathToShell in concatenation (.) or string at ./dos_it.pl line 761.
Use of uninitialized value $shell_conformance in concatenation (.) or string at ./dos_it.pl line 761.
The string that is generated is:
$ ps -ef | perl -ane '1..1 and /^(.*)CO?MM?A?N?D/ and $s=length $1;s/^.{$s}//; print "#F[1,2] $_"'
Perl version:
$ perl -v
This is perl 5, version 26, subversion 2 (v5.26.2) built for MSWin32-x64-multi-thread
That is a command for the Bourne shell (sh) or similar, but you gave it to the Windows shell (cmd) to execute. Execute the command using sh or similar (whether cygwin-built or otherwise) to get rid of the error.
By the way, you were using a Windows build of Perl (MSWin32-x64 arch), not a cygwin build of Perl (cygwin arch). That's not the cause of the error, as the program will run fine either way. That said, this "issue" will surely go away once you use a cygwin-built sh or similar to execute the command.
When I tried hash in command line as in the below example, I am getting syntax error. I tried using fat comma as well but still the same result. Can someone help me?
perl -e "%hash_ex=(as,wdesadc,afcsdc,esvdfvzdfvfv,1,sd,34,34);print $hash_ex{'1'};"
syntax error at -e line 1, near "};"
Execution of -e aborted due to compilation errors.
perl -e "%hash_ex=('a' => 1 , 'b' => 2);print $hash_ex {a};"
syntax error at -e line 1, near "};"
Execution of -e aborted due to compilation errors.
the problem is that your Shell also substitutes variables beginning with $:
# (on zsh and bash)
echo "%hash_ex=(as,wdesadc,afcsdc,esvdfvzdfvfv,1,sd,34,34);print $hash_ex{'1'};"
%hash_ex=(as,wdesadc,afcsdc,esvdfvzdfvfv,1,sd,34,34);print {'1'};
Because of this, you'll better use single qotes for your -E argument:
perl -e'%hash_ex=(as,wdesadc,afcsdc,esvdfvzdfvfv,1,sd,34,34);print $hash_ex{1};'
sd
if you really need single quotes (in this case you don't), you can use the q operator:
perl -E'say q~some non-interpolating string\t\n$_~'
some non-interpolating string\t\n$_
Or you can try to avoid the interpolating of your shell:
perl -e "%hash_ex=(as,wdesadc,afcsdc,esvdfvzdfvfv,1,sd,34,34);print \$hash_ex{'1'};"
You are using double quotes to pass your command to Perl. This will mean that the shell will first interpolate any variables in your string before it then passes the command to Perl. you can see this if you just run echo on the string with double quotes then single quotes. The output from echo will show what the shell is then passing to Perl
When the shell processes the text in the double quotes it interpolates the $hash_ex. Since this is not set in the shell this gets interpolated as nothing which means your print statement instead of being
print $hash_ex{a}
becomes
print {a}
So you need to wrap all your perl in singleqotes so that the shell does not interpolate any vars and passes the full string to perl as literal string.
I am executing my perl files in a batch. I am pasting all the name of the perl file in a batch file and executing it. I am giving a small demo of the file.
The batch file /10BT_run1.Amset contains:
Perl ../tools/test_driver_multi_aid_sequential.pl e2_h/l2_mode/set_bwprf #this is line 4 of the batch file
I am getting error like
Bareword found where operator expected at ./10BT_run1.Amset line 4, near "/tools /test_driver_multi_aid_sequential"
(Missing operator before test_driver_multi_aid_sequential?)
Bareword found where operator expected at ./10BT_run1.Amset line 4, near "/l2_mode/set_bwprf"
(Missing operator before et_bwprf?)
You are somehow executing the batch file (./10BT_run1.Amset) using perl instead of cmd.
you can run the perl files as argument to perl interpreter
perl "../tools/test_driver_multi_aid_sequential.pl e2_h/l2_mode/set_bwprf"
if you are going to use " in between the arguments separate those as escaping sequence like
\"
It will avoid the error that you have mentioned
I am writing the following command to extract the text in makefile:-
#awk '/Exported Layer/,/Total Polygons/' out_compare.err | perl -lane '$el=$F[3] if(/Exported Layer/); print "$el: $f[3]" if (/Total Polygons/);' | cat
But it is giving the following error:-
Can't modify constant item in scalar assignment at -e line 1, near "] if"
Execution of -e aborted due to compilation errors.
Would you guys like to suggest something? :-)
Make is oblivious to shell quoting in commands, so the $ characters in your Perl snippet are being interpreted as make variables $e and $F. These variables don't exist in your makefile and are being expanded as empty, leading to the Perl syntax errors you're seeing.
You need to escape the $ characters from make like this:
... perl -lane '$$el=$$F[3] if(/Exported Layer/); ...
See also the GNU Make manual.