CS 202 Computer Science II Lab

CS 202Computer Science II Lab Fall 2009 September 3

Today Topics • File Access Permissions • Text Editors • VI • Emacs • Compiling C++ Programs • Accessing Linux Remotely • Putty • SSH

File Access Permissions • user u/group g/other o • r or 4 read permission • wor 2 write permission • x or 1 execute permission • - no permission • chmod [options] file –change file or directory access permissions; (+/-/=) • chmod 755 file1 or chmod u=rwx,go=rx file1

Text editors - emacs • emacs/xemacs – are text editors used to create/modify files • emacs [filename] • $ emacs cs202file.cpp • Note: • C- = Control (Ctrl) key • M- = Meta key, generally the Alt key but can also be the Esc key • Essential Commands • C-x,C-s Save the file • C-x,C-w Save to a new file • C-x,C-c Exit emacs • C-x,u Undo last edit

Text editors – VI.. • There are two mode on this editor: • Command mode • Text-entry mode • vi [filename] • Back to command mode by using “Esc” key

.Text editors – VI. • Inserting text: • ‘i’ : insert before cursor • ‘a’ : append after cursor • ‘R’ : replace the text • ‘I’, ‘A’, ‘o’, ‘O’ • Deleting text: • ‘x’ : delete character under cursor • ‘dw’ : delete word under cursor • ‘dd’ : delete line under cursor

..Text editors – VI • Saving Files • ‘:w <filename>’ : save file as <filename> • ‘:w’ : save file with current name • Exit program: • ‘:wq’ : Save and Exit • ‘:q!’ : Exit without Save

showInfo • The content of “showInfo.cpp” #include <iostream> using namespace std; int main() { cout << "My name is : Ray" << endl; cout << "My email is : amayeh@cse.unr.edu" << endl; return 0; }

Compiling and Running C++ programs on Linux • The g++ compiler: On Linux and many Unix systems the standard C++ compiler is called g++.

Compiling Program • Primitive Compilation • $ g++ <programname.cpp> • Compile with specified output name • $ g++ -o <ouput filename> <programname.cpp> • Compile as object • $ g++ -c -o <object filename> <programname.cpp> • Linking Program • $ g++ -o <object filename> <pg1.cpp> <pg2.cpp>

Hello World • Using any text editor to create file called “hello.cpp” #include <iostream> using namespace std; //use standard namespace int main() { cout << "Hello World" << endl; return 0; } g++ -o hello hello.cpp ./hello

Remote Login • Software: • SSH Secure Shell Client • Putty • WinSCP • Host: • remote.ecc.unr.edu

Remote Login -Putty

Remote Login -SSH

Questions?

CS 202 Computer Science II Lab