[PATCH v2 1/3] kernel-shark: Provide parsing for quotation marks in Record command line

["Yordan Karadzhov (VMware)" <y.karadz@gmail.com>]

Shell-like parsing of quotation marks in the content of the "Command"
field of the "Record" dialog will give more options to the users.
For example, now we can trace

 python -c 'print("hello world")'

The patch also adds support for multi-line command options.

Suggested-by: Stephen Brennan <stephen@brennan.io>
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=204679
Signed-off-by: Yordan Karadzhov (VMware) <y.karadz@gmail.com>
---
 kernel-shark/src/KsCaptureDialog.cpp | 10 +++++--
 kernel-shark/src/KsUtils.cpp         | 41 ++++++++++++++++++++++++++++
 kernel-shark/src/KsUtils.hpp         |  2 ++
 3 files changed, 50 insertions(+), 3 deletions(-)

diff --git a/kernel-shark/src/KsCaptureDialog.cpp b/kernel-shark/src/KsCaptureDialog.cpp
index dc1e9b2..7c2ef46 100644
--- a/kernel-shark/src/KsCaptureDialog.cpp
+++ b/kernel-shark/src/KsCaptureDialog.cpp
@@ -170,7 +170,8 @@ QStringList KsCaptureControl::getArgs()
 		argv << _eventsWidget.getCheckedEvents(true);
 
 	argv << "-o" << outputFileName();
-	argv << _commandLineEdit.text().split(" ");
+
+	argv << KsUtils::splitArguments(_commandLineEdit.text());
 
 	return argv;
 }
@@ -350,7 +351,10 @@ void KsCaptureControl::_browse()
 
 void KsCaptureControl::_apply()
 {
-	emit argsReady(getArgs().join(" "));
+	QStringList argv = getArgs();
+
+	if (argv.count())
+		emit argsReady(argv.join(" "));
 }
 
 /** @brief Create KsCaptureMonitor widget. */
@@ -547,7 +551,7 @@ void KsCaptureDialog::_capture()
 	int argc;
 
 	if(_captureMon._argsModified) {
-		argv = _captureMon.text().split(" ");
+		argv = KsUtils::splitArguments(_captureMon.text());
 	} else {
 		argv = _captureCtrl.getArgs();
 	}
diff --git a/kernel-shark/src/KsUtils.cpp b/kernel-shark/src/KsUtils.cpp
index 58ce8c1..e99509f 100644
--- a/kernel-shark/src/KsUtils.cpp
+++ b/kernel-shark/src/KsUtils.cpp
@@ -257,6 +257,47 @@ QString getSaveFile(QWidget *parent,
 	return fileName;
 }
 
+/**
+ * Separate the command line arguments inside the string taking into account
+ * possible shell quoting and new lines.
+ */
+QStringList splitArguments(QString cmd)
+{
+	QString::SplitBehavior opt = QString::SkipEmptyParts;
+	int i, progress = 0, size;
+	QStringList argv;
+	QChar quote = 0;
+
+	/* Remove all new lines. */
+	cmd.replace("\\\n", " ");
+
+	size = cmd.count();
+	auto lamMid = [&] () {return cmd.mid(progress, i - progress);};
+	for (i = 0; i < size; ++i) {
+		if (cmd[i] == '\\') {
+			cmd.remove(i, 1);
+			size --;
+			continue;
+		}
+
+		if (cmd[i] == '\'' || cmd[i] == '"') {
+			if (quote.isNull()) {
+				argv << lamMid().split(" ", opt);
+				quote = cmd[i++];
+				progress = i;
+			} else if (quote == cmd[i]) {
+				argv << lamMid();
+				quote = 0;
+				progress = ++i;
+			}
+		}
+	}
+
+	argv << cmd.right(size - progress).split(" ", opt);
+
+	return argv;
+}
+
 }; // KsUtils
 
 /** A stream operator for converting QColor into KsPlot::Color. */
diff --git a/kernel-shark/src/KsUtils.hpp b/kernel-shark/src/KsUtils.hpp
index 7362c14..db1bf5e 100644
--- a/kernel-shark/src/KsUtils.hpp
+++ b/kernel-shark/src/KsUtils.hpp
@@ -130,6 +130,8 @@ QString getSaveFile(QWidget *parent,
 		    const QString &extension,
 		    QString &lastFilePath);
 
+QStringList splitArguments(QString cmd);
+
 }; // KsUtils
 
 /** Identifier of the Dual Marker active state. */
-- 
2.20.1