Merge pull request #69 from rest-for-physics/lobis-cli

CLI can now parse scientific notation integers

Author: lobis

src/Application.cxx

@@ -12,6 +12,7 @@
 #include <TRestRun.h>
 
 #include <csignal>
+#include <regex>
 #ifndef GEANT4_WITHOUT_G4RunManagerFactory
 #include <G4RunManagerFactory.hh>
 #endif
@@ -124,6 +125,17 @@ int GetSecondsFromFullTimeExpression(const char* expression) {
     return seconds;
 }
 
+int GetNumberFromStringScientific(string& s) {
+    // Allows to parse inputs of the form 1E5, 1.5E10 etc.
+    regex rgx("^([0-9]+.?([0-9]+)?)E([0-9]+)");
+    std::smatch matches;
+    if (std::regex_search(s, matches, rgx)) {
+        return int(stod(matches[1].str()) * TMath::Power(10, stoi(matches[3].str())));
+    } else {
+        return stoi(s);
+    }
+}
+
 Options ProcessCommandLineOptions(int argc, char* const argv[]) {
     Options options;
     options.argc = argc;
@@ -183,21 +195,22 @@ Options ProcessCommandLineOptions(int argc, char* const argv[]) {
                 exit(1);
             }
         } else if ((arg == "-n") || (arg == "--events")) {
-            if (i + 1 < argc) {  // Make sure we aren't at the end of argv!
-                options.nEvents =
-                    stoi(argv[++i]);  // Increment 'i' so we don't get the argument as the next argv[i].
+            if (i + 1 < argc) {        // Make sure we aren't at the end of argv!
+                string s = argv[++i];  // Increment 'i' so we don't get the argument as the next argv[i].
+                options.nEvents = GetNumberFromStringScientific(s);
                 if (options.nEvents <= 0) {
-                    cout << "--events option error: number of events must be > 0" << endl;
+                    cout << "--events option error: number of events must be > 0 (input: " << s << ")"
+                         << endl;
                     exit(1);
                 }
             } else {
                 cerr << "--events option requires one argument." << endl;
                 exit(1);
             }
         } else if ((arg == "-e") || (arg == "--entries")) {
-            if (i + 1 < argc) {  // Make sure we aren't at the end of argv!
-                options.nRequestedEntries =
-                    stoi(argv[++i]);  // Increment 'i' so we don't get the argument as the next argv[i].
+            if (i + 1 < argc) {        // Make sure we aren't at the end of argv!
+                string s = argv[++i];  // Increment 'i' so we don't get the argument as the next argv[i].
+                options.nRequestedEntries = GetNumberFromStringScientific(s);
                 if (options.nRequestedEntries <= 0) {
                     cout << "--entries option error: number of entries must be > 0" << endl;
                     exit(1);