Lecture Notes: 02 Linux Basics

Simple C Program #

(do this in in a terminal window with a file manager open to the same directory so we can watch stuff appear)

#include <stdio.h>

int
main(int argc, char* argv[])
{
    printf("Hello, C\n");
    return 0;
}

Compile that program:

$ gcc -o hello hello.c

Running commands on linux:

• First word is the name of the program executable file.
• Found by searching $PATH
• The rest of the words are command line arguments.

Run it:

$ ./hello

• Current directory isn’t in $PATH
• So we need to tell the shell where to find the program with ./

Handling arguments:

#include <stdio.h>

int
main(int argc, char* argv[])
{
    printf("argv has %d items:\n", argc);
    for (int ii = 0; ii < argc; ++ii) {
       printf(" - %d: %s\n", ii, argv[ii]); 
    }
    return 0;
}

Directories #

• Directories, pwd, cd, mkdir, rmdir

vim editor #

• syntax highlighting and auto-indentation
• editing modes
• combining
• navigating with relative moves
• cutting and copying lines and groups of lines
• navigating with ? and /

More complicated Linux commands #

• Demonstrate ;, ||, &&, >, », <, and &.