This is a place to record various command-line tricks and options I use in class. Due to a series of mis-translations involving 功夫 and Hollywood stereotypes, the magic you can do on the command line is traditionally called command-fu, command-line fu, script-fu, etc.

• clear scrolls so the next line is the top line of the terminal window. It does not remove anything, just scrolls.

• cat hello.c dumps the contents of hello.c to the terminal window.

• clang -S hello.c the -S flag means I want an assembly file, not a program and generates hello.s instead of a.out.

  Note the -S is capital; a lower-case -s means strip – i.e., remove all symbol table information from the binary (making it hard to link with other files and harder to debug, but making the file smaller.

• cpp hello.c runs the C pre-processor on hello.c, outputting the resulting .c file to the terminal

• cpp hello.c | less runs the C pre-processor on hello.c, outputting the resulting .c file into the less program so we can scan through it.

• clang -c hello.c the -c flag means I want an object file, not a program (i.e., stop before linking) and generates hello.o instead of a.out.

• clang hello.c -o hello the -o flag means name the output this instead of the default name and generates hello instead of a.out.

  Warning: if you do something like -o hello.c is over-writes your source code with the executable. Use -o with care.

• whatis printf or man -f printf lists the all of the manual pages that are titled printf

• apropos printf or man -k printf searches for manual pages that reference printf

• which clang shows the full path to the executable that will be run if you type clang