A shell prototype for arduino (or other extremely low memory devices). It can't be posix compliant in any way, but i try to make it familiar in some sense. Objectives for v.1:

• Low memory foot print at start (below 512 bytes of ram, and 9kb of flash)
• Shell with variables, very basic control flow (for, while, if) and functions
• Simple filesystem in flash (PROGMEM) and another one for eeprom (RW)
• Small and basic set of programs (ls, cat, echo, etc...)
• Simple interface of the shell with lcd's, serial port, etc... (through read/write calls)
• Support for scripts
• Support for boot scripts

• sh
• ls
• free
• times
• true
• false
• cat
• echo
• debug
• set

• execve Execute a file, with its environment
• exec The same as execve but without environment
• execl Variable argument list exec (you must end the list with a 0 or NULL)

• opendir Open a directory for reading the contents
• readdir Read next directory entry (call opendir first)
• closedir Close directory open by opendir call (needed to free memory used)
• rewinddir Point to the first element of the directory in a dir opened by opendir
• stat Check access to a file, return pointer to it
• open open a file, no close needed as all the information is in a variable used by the function calling open
• read load in a buffer a number of defined bytes from a file