TINYSH: MINIMAL SHELL=====================The purpose of the tinysh library is to provide a fully fonctionalshell support to a system as soon as we are able to read/writecharacters to/from a device. This suits particularly well to embeddedsystems when developers just made the uart work.As embedded systems often do not have full libc support, the libraryis written without any use of external functions nor include of anysystem header.The package contains a main.c file that can be used as an exampleto demonstrate tinysh usage.INSTALLATION------------Run the commands:./configuremake allYou just built the ./tinysh program. Run it and type "help" forfurther instructions.USING TINYSH------------The application must pass every single input character to functiontinysh_char_in. In addition, the application must provide a tinysh_char_out function to write characters to output deviceFor example:    void tinysh_char_out(unsigned char c)    {       put_char_to_uart(c);    }    ...    while(1)    {       unsigned char c;       c=get_char_from_uart(); /* we assume this fnt is blocking */       tinysh_char_in(c);    }    ... The application must provide each command by instantiating atinysh_cmd_t structure:typedef struct tinysh_cmd_t {  struct tinysh_cmd_t *parent; /* 0 if top level command */  char *name;                  /* command input name, not 0 */  char *help;                  /* help string, can be 0 */  char *usage;                 /* usage string, can be 0 */  tinysh_fnt_t function;       /* function to launch on cmd, can be 0 */  void *arg;                   /* current argument when function called */  struct tinysh_cmd_t *next;   /* must be set to 0 at init */  struct tinysh_cmd_t *child;  /* must be set to 0 at init */} tinysh_cmd_t;and passing the pointer to this structure to function tinysh_add_command.For example:void hello_fnt(int argc, char **argv){    printf("hello world\n");}tinysh_cmd_t hello_cmd={0,"hello","display hello","<cr>",    hello_fnt,0,0,0};...tinysh_add_command(&hello_cmd);...Read file main.c for more advanced usage.TINYSH SUPPORTS----------------command registration: application adds commands dynamically -sub-commands: allows any number of command level. For instance:     "$ memory read bytes <address> <size>" is supported and the     developer does not have to make a single "memory-read-bytes"    command.-contexts: the system remembers about contexts between inputs,     for instance, from the previous example, typing "memory<cr>"    leads to prompt "$ memory >" so the next input can be simply    "read bytes <xx> <yy>". Use "/" to return to top level.-previous commands retrieval: by using CTRL-P and CTRL-N-partial command word: there is no need to type the whole    command word if there is no ambiguity on what has already been     typed.-auto-completion: using <TAB>-help and usage display: using "?", display help related to current     input line.-string to decimal/hexadecimal conversion: this is not really a shell    feature but this is often very useful in the environment where    tinysh can be used. Strings starting with 0x are converted to     hexadecimal.-echo control: it is possible for the application to enable/disable    character echo.-dynamic argument: to allow several commands to share the same function     callback, the callback can retrieve an additional argument for the     current  command.-prompt change: application can change shell prompt.TINYSH DOES NOT SUPPORT------------------------line edition: only backspace is supported-multiple shells within the same data space: this could be done    by adding a new parameter to all functions. This parameter would    be a pointer to a structure containing all currently global     variables. As tinysh is not allowed to use dynamic memory    allocation (which may not be available in the system), an    empty structure (all 0s) must be provided by the application at    shell instance init. As we want to keep simple things simple,    the tinysh library should support one instance and current     functions must remain unchanged by using macros. This is to    be done.-application driven context: it is not possible to have contexts    such as "$ subsystem <subsys-name> > " if <subsys-name> is not    determined at compile time. It will added when there will be a     real need for it.BUGS----Please report bugs to "Michel Gutierrez"<mig@nerim.net>