Notes

ll = all files not normally shown. files whose names start with "."
vim hello.c
play around with "vimtutor" to learn vim
to get out type ":q" (escape command first)
ls = tells you what files (not dot files) are in the directory.
ls-a: shows me all files including whose name starts with "."
mv hello.c .hello.c => moves file
Nothing special with files whose name start with "."
In UNIX, you won't see "." files
".." is present in every directory. Chains back to the previous directory
"~" (Tilda) is shorthand for the home directory.
cd . => nothing happens
"-l" => long format | owner group size of file last-modified date
"-F" => adds some hint to tell you what kind of file. Tags single character after filename. / if a directory, * if program
Shorthand writing ex. "-alF"
alias "ll" = 'sl - etc'. Type "alias" to see all possible aliases
Before you set up an alias, you need to make sure there are no already used commands
cat <filename>.c => dumps file onto the window. You can type multiple files with space.
cat <filename>.c <filename>.c
Compiler => gcc <filename>.c. Type "ll" afterward
bash will look for commands in certain places
"which ls" will tell you where the command is.
to see output get "pwd" and then add file. (ex. pwd/a.out or ~/tmp.out or ./out"
In "./a.out", the dot refers as current directory
You can rename the file output by writting "ggc <filename>.c -o <new filename>". When you type ll, the output is highlighted and tagged with an *
In any UNIX/LINUX like system, ".c" is a c-program.
GCC does two steps as once, compilation and link. Only one step: "ggc -c hello.c". You get an object file after typing "ll". The file is not complete, part of the program that makes the whole program. Once you have the object file, run ggc again but with the object: "ggc hello.o -o hello". This step is called linking; you link all the ".o" files together. Removed intermediate ".o" file.
To save a vim file, press ESC and then type :x to save and exit.
To see machine code, type "filename".o. Not readable code.
ggc -c -Wall hello.c
-Wall => checks to see if functions were explicitly declared. Simply declare the function at the top line (above your main file). This is called function declaration/prototype/declaration. Minimum required for C program. You at least need to declare it before you even write it.
The "printf" line is included in the header file <stdio.h>. Please find header file in some predefined system directory. "Paste the content of stdio into the file" ~ Copy and Paste
locate stdio.h. The file were are using starts with user/include/...
man ls => manual page for ls
<> = find file in predefines sys directory
"" = find file here
rm *.o hello => remove anything with .o
You can update the header file to include more/ fewer parameters to a function you defined somewhere else