MT#55289 Add del-value helper

Move perl code which actually modifies yml file to separate helper as
there is no sense to recreate it every call of 'ngcpcfg del'.

Change-Id: Iab9e023318cf9798bdb10d89b08dc2afe125c495

Makefile

@@ -6,6 +6,7 @@ BASH_SCRIPTS = \
 	sbin/ngcpcfg
 PERL_SCRIPTS = \
 	lib/NGCP/Template.pm \
+	helper/del-value \
 	helper/set-value \
 	helper/sort-yml \
 	helper/sync-db \

debian/ngcp-ngcpcfg.install

@@ -4,6 +4,7 @@ functions/logs              usr/share/ngcp-ngcpcfg/functions/
 functions/main              usr/share/ngcp-ngcpcfg/functions/
 helper/cat-yml              usr/share/ngcp-ngcpcfg/helper/
 helper/check-for-mysql      usr/share/ngcp-ngcpcfg/helper/
+helper/del-value            usr/share/ngcp-ngcpcfg/helper/
 helper/fileformat_version   usr/share/ngcp-ngcpcfg/helper/
 helper/instance-info        usr/share/ngcp-ngcpcfg/helper/
 helper/instances-info       usr/share/ngcp-ngcpcfg/helper/

helper/del-value

@@ -0,0 +1,48 @@
+#!/usr/bin/perl -wCSD
+
+use strict;
+use warnings;
+
+use YAML::XS;
+use Scalar::Util qw(looks_like_number);
+
+my ($file, $option) = @ARGV;
+
+unless (defined($file)) {
+    print {*STDERR} ("1st parameter 'file' is not defined\n");
+    exit (1);
+}
+unless (defined($option)) {
+    print {*STDERR} ("2nd parameter 'option' is not defined\n");
+    exit (1);
+}
+
+my $yaml = YAML::XS::LoadFile($file);
+my $valref = \$yaml;
+
+my @path = split(/\./, $option);
+my $delete_element = pop(@path);
+
+for my $component (@path) {
+    if (ref($valref) eq 'SCALAR' && defined(${$valref})) {
+        print {*STDERR} ("Key resolved to a SCALAR at '$component'; cannot continue.\n");
+        exit (1);
+    }
+    elsif (looks_like_number($component) && (! defined(${$valref}) || ref(${$valref}) eq 'ARRAY')) {
+        $valref = \${$valref}->[$component];
+    }
+    elsif ($component eq 'APPEND' && ref($$valref) eq 'ARRAY') {
+        $valref = \${$valref}->[$#{$$valref}+1];
+    }
+    elsif (! defined(${$valref}) || ref(${$valref}) eq 'HASH') {
+        $valref = \${$valref}->{$component};
+    }
+    else {
+        print {*STDERR} ("Key resolved to a " . ref(${$valref}) . " reference; refusing to overwrite.\n");
+        exit (1);
+    }
+}
+
+delete ${$valref}->{$delete_element};
+
+YAML::XS::DumpFile($file, $yaml);

scripts/del

@@ -60,39 +60,14 @@ option="$2"
 [ -z "${option}" ] && ( log_error "missing option to set. Exiting." ; exit 1)
 log_debug "Deleting option '${option}' from '${file}'"
 
-perl_line="delete \$yaml->{${option//./\}->\{}};"
-log_debug "perl line: ${perl_line}"
-
-tmp=$(mktemp -t ngcpcfg-del.XXXXXXXXXX)
-log_debug "Temporary perl file: ${tmp}"
-
-cat > "${tmp}" << EOF
-use strict;
-use warnings;
-use YAML::XS;
-my \$file="${file}";
-my \$yaml = YAML::XS::LoadFile("\$file");
-
-${perl_line}
-
-YAML::XS::DumpFile(\$file, \$yaml);
-EOF
-
-log_debug "perl -wCSD \"${tmp}\" || RC=$?"
-perl -wCSD "${tmp}" || RC=$?
-
+log_debug "${HELPER}/del-value '${file}' '${option}' || RC=\$?"
+"${HELPER}/del-value" "${file}" "${option}" || RC=$?
 
 if [ "${RC}" = "0" ] && "${b_show_diff:-false}"; then
   log_debug "${SCRIPTS}/diff || true"
   "${SCRIPTS}"/diff || true
 fi
 
-if [ -n "${DEBUG:-}" ] ; then
-  log_debug "Not removing temporary file ${tmp}"
-else
-  rm -f "${tmp}"
-fi
-
 exit ${RC:-0}
 
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