Do not use double-quotes on strings that do not need interpolation

Using double-quotes imposes a small performance penalty as the perl
parser needs to check if any interpolation is needed. Use double-quotes
only when the string contains single-quotes. Ideally we'd use
double-quotes too for escaped meta-characters that might otherwise be
confusing to immediately see if they need interpolation or not, but the
policy does not (currently) allow to ignore these.

Fixes ValuesAndExpressions::ProhibitInterpolationOfLiterals.

Warned-by: perlcritic

4 files changed, 94 insertions, 92 deletions

diff --git a/dselect/methods/Dselect/Ftp.pm b/dselect/methods/Dselect/Ftp.pm
index 5c995d512..dc0cc3a53 100644
--- a/dselect/methods/Dselect/Ftp.pm
+++ b/dselect/methods/Dselect/Ftp.pm
@@ -27,11 +27,11 @@ our %config;
 sub nb {
   my $nb = shift;
   if ($nb > 1024**2) {
-    return sprintf("%.2fM", $nb / 1024**2);
+    return sprintf('%.2fM', $nb / 1024**2);
   } elsif ($nb > 1024) {
-    return sprintf("%.2fk", $nb / 1024);
+    return sprintf('%.2fk', $nb / 1024);
   } else {
-    return sprintf("%.2fb", $nb);
+    return sprintf('%.2fb', $nb);
   }
 
 }
@@ -97,7 +97,7 @@ sub edit_config {
       $i++;
     }
     print "\nEnter a command (a=add e=edit d=delete q=quit m=mirror list) \n";
-    print "eventually followed by a site number : ";
+    print 'eventually followed by a site number : ';
     chomp($_ = <STDIN>);
     /q/i && last;
     /a/i && add_site();
@@ -113,8 +113,8 @@ sub edit_config {
   }
 
   print "\n";
-  $config{use_auth_proxy} = yesno($config{use_auth_proxy} ? "y" : "n",
-                                      "Go through an authenticated proxy");
+  $config{use_auth_proxy} = yesno($config{use_auth_proxy} ? 'y' : 'n',
+                                  'Go through an authenticated proxy');
 
   if ($config{use_auth_proxy}) {
     print "\nEnter proxy hostname [$config{proxyhost}] : ";
@@ -144,16 +144,16 @@ sub edit_config {
 
 sub add_site {
   my $pas = 1;
-  my $user = "anonymous";
+  my $user = 'anonymous';
   my $email = `whoami`;
   chomp $email;
   $email .= '@' . `cat /etc/mailname || dnsdomainname`;
   chomp $email;
-  my $dir = "/debian";
+  my $dir = '/debian';
 
-  push (@{$config{site}}, [ "", $dir, [ "dists/stable/main",
-                                          "dists/stable/contrib",
-					  "dists/stable/non-free" ],
+  push (@{$config{site}}, [ '', $dir, [ 'dists/stable/main',
+                                        'dists/stable/contrib',
+                                        'dists/stable/non-free' ],
                                $pas, $user, $email ]);
   edit_site($config{site}[@{$config{site}} - 1]);
 }
@@ -167,7 +167,7 @@ sub edit_site {
   chomp($_ = <STDIN>);
   $site->[0] = $_ || $site->[0];
 
-  print "\nUse passive mode [" . ($site->[3] ? "y" : "n") ."] : ";
+  print "\nUse passive mode [" . ($site->[3] ? 'y' : 'n') . '] : ';
   chomp($_ = <STDIN>);
   $site->[3] = (/y/i ? 1 : 0) if ($_);
 
@@ -202,9 +202,9 @@ sub yesno($$) {
 
   my ($res, $r);
   $r = -1;
-  $r = 0 if $d eq "n";
-  $r = 1 if $d eq "y";
-  die "Incorrect usage of yesno, stopped" if $r == -1;
+  $r = 0 if $d eq 'n';
+  $r = 1 if $d eq 'y';
+  die 'Incorrect usage of yesno, stopped' if $r == -1;
   while (1) {
     print $msg, " [$d]: ";
     $res = <STDIN>;
@@ -229,7 +229,7 @@ sub do_connect {
 
 	if ($useproxy) {
 	    $remotehost = $proxyhost;
-	    $remoteuser = $username . "@" . $ftpsite;
+	    $remoteuser = $username . '@' . $ftpsite;
 	} else {
 	    $remotehost = $ftpsite;
 	    $remoteuser = $username;
@@ -248,13 +248,13 @@ sub do_connect {
 		$ftp->_PASS($proxypassword);
 	    }
 	    print "Login as $username...\n";
-	    if ($pass eq "?") {
-		    print "Enter password for ftp: ";
-		    system("stty", "-echo");
+	    if ($pass eq '?') {
+		    print 'Enter password for ftp: ';
+		    system('stty', '-echo');
 		    $rpass = <STDIN>;
 		    chomp $rpass;
 		    print "\n";
-		    system("stty", "echo");
+		    system('stty', 'echo');
 	    } else {
 		    $rpass = $pass;
 	    }
@@ -271,17 +271,17 @@ sub do_connect {
 	}
 
 	if ($exit) {
-	    if (yesno ("y", "Retry connection at once")) {
+	    if (yesno ('y', 'Retry connection at once')) {
 		next TRY_CONNECT;
 	    } else {
-		die "error";
+		die 'error';
 	    }
 	}
 
 	last TRY_CONNECT;
     }
 
-#    if(!$ftp->pasv()) { print $ftp->message . "\n"; die "error"; }
+#    if(!$ftp->pasv()) { print $ftp->message . "\n"; die 'error'; }
 
     return $ftp;
 }
@@ -334,7 +334,7 @@ sub do_mdtm {
 
 #	print "[$#files]";
 
-	# get the date components from the output of "ls -l"
+	# get the date components from the output of 'ls -l'
 	if ($files[0] =~
 	    /([^ ]+ *){5}[^ ]+ ([A-Z][a-z]{2}) ([ 0-9][0-9]) ([0-9 ][0-9][:0-9][0-9]{2})/) {
 
@@ -364,13 +364,13 @@ sub do_mdtm {
 		$hours = 0; $minutes = 0;
 		$year = $yearOrTime - 1900;
 	    } else {
-		die "Cannot parse year-or-time";
+		die 'Cannot parse year-or-time';
 	    }
 
 	    # build a system time
 	    $time = timegm (0, $minutes, $hours, $day, $month, $year);
 	} else {
-	    die "Regexp match failed on LIST output";
+	    die 'Regexp match failed on LIST output';
 	}
     }
 
diff --git a/dselect/methods/ftp/install b/dselect/methods/ftp/install
index 615fa8f75..de365e334 100755
--- a/dselect/methods/ftp/install
+++ b/dselect/methods/ftp/install
@@ -42,7 +42,7 @@ my $vardir = $ARGV[0];
 my $method = $ARGV[1];
 my $option = $ARGV[2];
 
-if ($option eq "manual" ) {
+if ($option eq 'manual') {
   print "manual mode not supported yet\n";
   exit 1;
 }
@@ -115,14 +115,14 @@ my %curpkgs;
 sub procstatus {
     my (%flds, $fld);
     open(my $status_fh, '<', "$vardir/status") or
-        die "Could not open status file";
+        die 'Could not open status file';
     while (%flds = getblk($status_fh), %flds) {
 	if($flds{'status'} =~ /^install ok/) {
 	    my $cs = (split(/ /, $flds{'status'}))[2];
-	    if(($cs eq "not-installed") ||
-	       ($cs eq "half-installed") ||
-	       ($cs eq "config-files")) {
-		$curpkgs{$flds{'package'}} = "";
+	    if (($cs eq 'not-installed') ||
+	        ($cs eq 'half-installed') ||
+	        ($cs eq 'config-files')) {
+		$curpkgs{$flds{'package'}} = '';
 	    } else {
 		$curpkgs{$flds{'package'}} = $flds{'version'};
 	    }
@@ -135,7 +135,7 @@ procstatus();
 sub dcmpvers {
     my($a, $p, $b) = @_;
     my ($r);
-    $r = system("dpkg", "--compare-versions", "$a", "$p", "$b");
+    $r = system('dpkg', '--compare-versions', "$a", "$p", "$b");
     $r = $r/256;
     if ($r == 0) {
 	return 1;
@@ -164,7 +164,7 @@ sub procpkgfile {
 	@files = split(/[\s\n]+/, $flds{'filename'});
 	@sizes = split(/[\s\n]+/, $flds{'size'});
 	@md5sums = split(/[\s\n]+/, $flds{'md5sum'});
-	if ( defined($ver) && ( ($ver eq "") || dcmpvers( $ver, "lt", $flds{'version'} ) )) {
+	if (defined($ver) && (($ver eq '') || dcmpvers($ver, 'lt', $flds{'version'}))) {
 	    $pkgs{$pkg} = [ $flds{'version'}, [ @files ], $site ];
 	    $curpkgs{$pkg} = $flds{'version'};
 	}
@@ -207,7 +207,7 @@ my $dldir = $config{dldir};
 sub md5sum($) {
     my $fn = shift;
     my $m = `md5sum $fn`;
-    $m = (split(" ", $m))[0];
+    $m = (split(' ', $m))[0];
     $md5sums{"$dldir/$fn"} = $m;
     return $m;
 }
@@ -236,8 +236,8 @@ foreach $pkg (keys(%pkgs)) {
 	    $size = -s "$dldir/$fn";
 	    if($info[1] > $size) {
 		# partial download
-		if(yesno("y", "continue file: $fn (" . nb($size) ."/" .
-		              nb($info[1]). ")")) {
+		if (yesno('y', "continue file: $fn (" . nb($size) . '/' .
+		               nb($info[1]) . ')')) {
 		    $downloads{$fn} = $size;
 		    $totsize += $csize - int($size/1024);
 		} else {
@@ -259,7 +259,7 @@ foreach $pkg (keys(%pkgs)) {
 	} else {
 	    my $ffn = $fn;
 	    $ffn =~ s/binary-[^\/]+/.../;
-	    print "want: " .
+	    print 'want: ' .
 	          $config{site}[$pkgfiles{$fn}[2]][0] . " $ffn (${csize}k)\n";
 	    $downloads{$fn} = 0;
 	    $totsize += $csize;
@@ -277,18 +277,19 @@ print "Available space in $dldir: ${avsp}k\n";
 #chomp $avsp;
 
 if($totsize == 0) {
-    print "Nothing to get.";
+    print 'Nothing to get.';
 } else {
     if($totsize > $avsp) {
 	print "Space required is greater than available space,\n";
 	print "you will need to select which items to get.\n";
     }
 # ask user which files to get
-    if(($totsize > $avsp) || yesno("n", "Do you want to select the files to get")) {
+    if (($totsize > $avsp) ||
+        yesno('n', 'Do you want to select the files to get')) {
 	$totsize = 0;
 	my @files = sort(keys(%downloads));
 	my $fn;
-	my $def = "y";
+	my $def = 'y';
 	foreach $fn (@files) {
 	    my @info = @{$pkgfiles{$fn}};
 	    my $csize = int($info[1] / 1024) + 1;
@@ -300,10 +301,10 @@ if($totsize == 0) {
 		if(yesno($def, $downloads{$fn}
 			 ? "download: $fn ${rsize}k/${csize}k (total = ${totsize}k)"
 			 : "download: $fn ${rsize}k (total = ${totsize}k)")) {
-		    $def = "y";
+		    $def = 'y';
 		    $totsize += $rsize;
 		} else {
-		    $def = "n";
+		    $def = 'n';
 		    delete $downloads{$fn};
 		}
 	    }
@@ -326,7 +327,7 @@ sub download() {
     $cp = -1;
     foreach (@{$site->[2]}) {
       $cp++;
-      $pre_dist[$cp] = "";
+      $pre_dist[$cp] = '';
       $n = (s#\.\./#../#g);
       next if (! $n);
       if (m#^((?:\.\./){$n}(?:[^/]+/){$n})#) {
@@ -351,10 +352,10 @@ sub download() {
 
     my ($fn,$rsize,$res,$pre);
     foreach $fn (@getfiles) {
-        $pre = $pre_dist[$pkgfiles{$fn}[3]] || "";
+        $pre = $pre_dist[$pkgfiles{$fn}[3]] || '';
 	if ($downloads{$fn}) {
 	    $rsize = ${pkgfiles{$fn}}[1] - $downloads{$fn};
-	    print "getting: $pre$fn (". nb($rsize) . "/" .
+	    print "getting: $pre$fn (" . nb($rsize) . '/' .
 	          nb($pkgfiles{$fn}[1]) . ")\n";
 	} else {
 	    print "getting: $pre$fn (". nb($pkgfiles{$fn}[1]) . ")\n";
@@ -399,11 +400,12 @@ sub download() {
 
 # download stuff (protect from ^C)
 if($totsize != 0) {
-    if(yesno("y", "\nDo you want to download the required files")) {
+    if (yesno('y', "\nDo you want to download the required files")) {
       DOWNLOAD_TRY: while (1) {
 	  print "Downloading files... use ^C to stop\n";
 	  eval {
-	      if ((download() == 1) && yesno("y", "\nDo you want to retry downloading at once")) {
+	      if ((download() == 1) &&
+	          yesno('y', "\nDo you want to retry downloading at once")) {
 		  next DOWNLOAD_TRY;
 	      }
 	  };
@@ -415,7 +417,7 @@ if($totsize != 0) {
 	        undef $::ftp;
 	      }
 	      print "FTP ERROR\n";
-              if (yesno("y", "\nDo you want to retry downloading at once")) {
+              if (yesno('y', "\nDo you want to retry downloading at once")) {
 		  # get the first $fn that foreach would give:
 		  # this is the one that got interrupted.
 		my $ffn;
@@ -425,7 +427,7 @@ if($totsize != 0) {
 		}
 	        my $size = -s "$dldir/$fn";
 		# partial download
-		if(yesno("y", "continue file: $fn (at $size)")) {
+		if (yesno('y', "continue file: $fn (at $size)")) {
 		    $downloads{$fn} = $size;
 		} else {
 		    $downloads{$fn} = 0;
@@ -497,9 +499,9 @@ sub prcdeb($$) {
 	return 0;
     }
     if($vers{$pkg}) {
-	if(dcmpvers($vers{$pkg}, "eq", $ver)) {
+	if (dcmpvers($vers{$pkg}, 'eq', $ver)) {
 	    $files{$pkg . $ver} = [ $files{$pkg . $ver }, "$dir/$fn" ];
-	} elsif (dcmpvers($vers{$pkg}, "gt", $ver)) {
+	} elsif (dcmpvers($vers{$pkg}, 'gt', $ver)) {
 	    print "old version\n";
 	    unlink $fn;
 	} else { # else $ver is gt current version
@@ -520,7 +522,7 @@ sub prcdeb($$) {
 sub prcfile() {
     my ($fn) = $_;
     if (-f $fn and $fn ne '.') {
-        my $dir = ".";
+        my $dir = '.';
 	if (length($File::Find::dir) > length($dldir)) {
             $dir = substr($File::Find::dir, length($dldir)+1);
 	}
@@ -558,7 +560,7 @@ sub prcfile() {
 find(\&prcfile, "$dldir/");
 
 # install .debs
-if(yesno("y", "\nDo you want to install the files fetched")) {
+if (yesno('y', "\nDo you want to install the files fetched")) {
     print "Installing files...\n";
     #Installing pre-dependent package before !
     my (@flds, $package, @filename, $r);
@@ -574,7 +576,7 @@ if(yesno("y", "\nDo you want to install the files fetched")) {
       if ($r) { print "DPKG ERROR\n"; $exit = 1; }
     }
     #Installing other packages after
-    $r = system("dpkg", "-iGREOB", $dldir);
+    $r = system('dpkg', '-iGREOB', $dldir);
     if($r) {
 	print "DPKG ERROR\n";
 	$exit = 1;
@@ -584,7 +586,7 @@ if(yesno("y", "\nDo you want to install the files fetched")) {
 sub removeinstalled {
     my $fn = $_;
     if (-f $fn and $fn ne '.') {
-        my $dir = ".";
+        my $dir = '.';
 	if (length($File::Find::dir) > length($dldir)) {
             $dir = substr($File::Find::dir, length($dldir)+1);
 	}
@@ -593,7 +595,7 @@ sub removeinstalled {
 	    if(!defined($pkg) || !defined($ver)) {
 		print "Could not get info for: $dir/$fn\n";
 	    } else {
-		if($curpkgs{$pkg} and dcmpvers($ver, "le", $curpkgs{$pkg})) {
+		if ($curpkgs{$pkg} and dcmpvers($ver, 'le', $curpkgs{$pkg})) {
 		    print "deleting: $dir/$fn\n";
 		    unlink $fn;
 		} else {
@@ -608,7 +610,7 @@ sub removeinstalled {
 
 # remove .debs that have been installed (query user)
 # first need to reprocess status file
-if(yesno("y", "\nDo you wish to delete the installed package (.deb) files?")) {
+if (yesno('y', "\nDo you wish to delete the installed package (.deb) files?")) {
     print "Removing installed files...\n";
     %curpkgs = ();
     procstatus();
@@ -616,7 +618,7 @@ if(yesno("y", "\nDo you wish to delete the installed package (.deb) files?")) {
 }
 
 # remove whole ./debian directory if user wants to
-if(yesno("n", "\nDo you want to remove $dldir directory?")) {
+if (yesno('n', "\nDo you want to remove $dldir directory?")) {
     rmtree("$dldir");
 }
 
diff --git a/dselect/methods/ftp/setup b/dselect/methods/ftp/setup
index a5cc9af62..26da50d36 100755
--- a/dselect/methods/ftp/setup
+++ b/dselect/methods/ftp/setup
@@ -32,7 +32,7 @@ my $vardir = $ARGV[0];
 my $method = $ARGV[1];
 my $option = $ARGV[2];
 
-if ($option eq "manual") {
+if ($option eq 'manual') {
     print "Manual package installation.\n";
     exit 0;
 }
@@ -48,11 +48,11 @@ chomp $logname;
 my $host = `cat /etc/mailname || dnsdomainname`;
 chomp $host;
 
-$config{dldir} = "debian";
+$config{dldir} = 'debian';
 $config{use_auth_proxy} = 0;
-$config{proxyhost} = "";
+$config{proxyhost} = '';
 $config{proxylogname} = $logname;
-$config{proxypassword} = "";
+$config{proxypassword} = '';
 
 my $methdir = "$vardir/methods/ftp";
 my $exit = 0;
@@ -63,8 +63,8 @@ if (-f "$methdir/vars") {
 }
 
 chdir "$methdir";
-if (! -d "debian") {
-    mkdir "debian", 0755;
+if (! -d 'debian') {
+    mkdir 'debian', 0755;
 }
 # get info from user
 
@@ -102,7 +102,7 @@ Eg:  use auth proxy: y
 EOM
 
 if (! $config{done}) {
-  view_mirrors() if (yesno("y", "Would you like to see a list of ftp mirrors"));
+  view_mirrors() if (yesno('y', 'Would you like to see a list of ftp mirrors'));
   add_site();
 }
 edit_config($methdir);
@@ -127,10 +127,10 @@ sub download() {
     foreach $dist (@dists) {
 	my $dir = "$dist/binary-$arch";
 	print "Checking $dir...\n";
-#	if(!$ftp->pasv()) { print $ftp->message . "\n"; die "error"; }
+#	if (!$ftp->pasv()) { print $ftp->message . "\n"; die 'error'; }
 	my @dirlst = $ftp->ls("$dir/");
 	my $got_pkgfile = 0;
-	my $line = "";
+	my $line = '';
 	foreach $line (@dirlst) {
 	    if($line =~ /Packages/) {
 		$got_pkgfile=1;
@@ -157,8 +157,8 @@ eval {
 };
 if($@) {
     $ftp->quit();
-    print "FTP ERROR - ";
-    if ($@ eq "connect") {
+    print 'FTP ERROR - ';
+    if ($@ eq 'connect') {
 	print "config was untested\n";
     } else {
 	print "$@\n";
diff --git a/dselect/methods/ftp/update b/dselect/methods/ftp/update
index 92b82782c..bb3050c0b 100755
--- a/dselect/methods/ftp/update
+++ b/dselect/methods/ftp/update
@@ -33,17 +33,17 @@ my $vardir = $ARGV[0];
 my $method = $ARGV[1];
 my $option = $ARGV[2];
 
-if ($option eq "manual") {
+if ($option eq 'manual') {
     print "Enter package file names or a blank line to finish\n";
     while(1) {
-	print "Enter package file name:";
+	print 'Enter package file name:';
 	my $fn = <STDIN>;
 	chomp $fn;
-	if ( $fn == "") {
+	if ($fn == '') {
 	    exit 0;
 	}
 	if ( -f $fn ) {
-	    system ("dpkg", "--merge-avail", $fn);
+	    system('dpkg', '--merge-avail', $fn);
 	} else {
 	    print "Could not find $fn, try again\n";
 	}
@@ -134,36 +134,36 @@ foreach (@{$config{site}}) {
 	}
 
 	if ($must_get) {
-	    -f "Packages.gz" and unlink "Packages.gz";
-	    -f "Packages" and unlink "Packages";
+	    -f 'Packages.gz' and unlink 'Packages.gz';
+	    -f 'Packages' and unlink 'Packages';
 	    my $size = 0;
 
 	  TRY_GET_PACKAGES:
 	    while (1) {
 		if ($size) {
-		    print " Continuing ";
+		    print ' Continuing ';
 		} else {
-		    print " Getting ";
+		    print ' Getting ';
 		}
 		print "Packages file from $dir...\n";
 		eval {
-		    if ($ftp->get("$dir/Packages.gz", "Packages.gz", $size)) {
-			if (system("gunzip", "Packages.gz")) {
+		    if ($ftp->get("$dir/Packages.gz", 'Packages.gz', $size)) {
+			if (system('gunzip', 'Packages.gz')) {
 			    print "  Couldn't gunzip Packages.gz, stopped";
-			    die "error";
+			    die 'error';
 			}
 		    } else {
 			print "  Couldn't get Packages.gz from $dir !!! Stopped.";
-			die "error";
+			die 'error';
 		    }
 		};
 		if ($@) {
-		    $size = -s "Packages.gz";
+		    $size = -s 'Packages.gz';
 		    if (ref($ftp)) {
 		      $ftp->abort();
 		      $ftp->quit();
 		    };
-		    if (yesno ("y", "Transfer failed at $size: retry at once")) {
+		    if (yesno ('y', "Transfer failed at $size: retry at once")) {
                          $ftp = do_connect ($site->[0], # Ftp server
                            $site->[4], # username
                            $site->[5], # password
@@ -180,15 +180,15 @@ foreach (@{$config{site}}) {
 			}
 			next TRY_GET_PACKAGES;
 		    } else {
-			die "error";
+			die 'error';
 		    }
 		}
 		last TRY_GET_PACKAGES;
 	    }
 
-	    if(!rename "Packages", "Packages.$site->[0].$dist") {
+	    if (!rename 'Packages', "Packages.$site->[0].$dist") {
 		print "  Couldn't rename Packages to Packages.$site->[0].$dist";
-		die "error";
+		die 'error';
 	    } else {
 		# set local Packages file to same date as the one it mirrors
 		# to allow comparison to work.
@@ -228,11 +228,11 @@ However if you have only downloaded a Package files from non-main
 distributions you might not want to do this.
 
 EOM
-    if (yesno ("y", "Do you want to clear available list")) {
+    if (yesno ('y', 'Do you want to clear available list')) {
 	print "Clearing...\n";
-	if(system("dpkg", "--clear-avail")) {
-	    print "dpkg --clear-avail failed.";
-	    die "error";
+	if (system('dpkg', '--clear-avail')) {
+	    print 'dpkg --clear-avail failed.';
+	    die 'error';
 	}
     }
 }
@@ -243,7 +243,7 @@ if (!$packages_modified) {
     my $file;
 
     foreach $file (@pkgfiles) {
-	if(system ("dpkg", "--merge-avail", $file)) {
+	if (system('dpkg', '--merge-avail', $file)) {
 	    print "Dpkg merge available failed on $file";
 	    $exit = 1;
 	}