source: trunk/user/ksh/ksh.c @ 407

///////////////////////////////////////////////////////////////////////////////
// File   :  ksh.c
// Date   :  October 2017
// Author :  Alain Greiner
///////////////////////////////////////////////////////////////////////////////
// This single thread application implement a simple shell for ALMOS-MKH.
///////////////////////////////////////////////////////////////////////////////

#include <nostdio.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define CMD_MAX_SIZE   (256)    // max number of characters in one command
#define LOG_DEPTH      (256)    // max number of registered commands 
#define MAX_ARGS           (32)     // max number of arguments in a command
#define FIFO_SIZE      (1024)   // FIFO depth for recursive ls

////////////////////////////////////////////////////////////////////////////////
//         Structures
////////////////////////////////////////////////////////////////////////////////

// one entry in the registered commands array
typedef struct log_entry_s 
{
        char          buf[CMD_MAX_SIZE];
        unsigned int  count;
}
log_entry_t;

// one entry in the supported command types array
typedef struct ksh_cmd_s 
{
        char * name;
        char * desc;
        void   (*fn)( int , char ** );
}
ksh_cmd_t;


////////////////////////////////////////////////////////////////////////////////
//         Global Variables
////////////////////////////////////////////////////////////////////////////////

ksh_cmd_t       cmd[];                    // array of supported commands

log_entry_t     log_entries[LOG_DEPTH];   // array of registered commands

unsigned int    ptw;                      // write pointer in log_entries[]
unsigned int    ptr;                      // read pointer in log_entries[]

////////////////////////////////////////////////////////////////////////////////
//         Shell  Commands
////////////////////////////////////////////////////////////////////////////////

/////////////////////////////////////////////
static void cmd_cat( int argc , char **argv )
{
        char         * path;

        if (argc != 2) 
    {
                printf("usage: cat pathname\n");
                return;
        }

        path = argv[1];

    printf("error: not implemented yet\n");

/*
        // open the file
        fd = open( path , O_RDONLY , 0 );
        if (fd < 0) 
    {
                printf("error: cannot open %s\n", path);
                goto exit;
        }

        // get file size 
        if (stat(path, &st) == -1)
    {
                printf("error: cannot stat %s\n", path);
                goto exit;
        }
        if (S_ISDIR(st.st_mode)) {
                printf("error: %s is a directory\n", path);
                goto exit;
        }
        size = st.st_size;

        // mmap the file 
        buf = mmap(NULL, size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
        if (buf == NULL || buf == (char *)-1) {
                printf("error: cannot map %s\n", path);
                goto exit;
        }

        // set terminating '0' XXX
        buf[size-1] = 0;

        // display the file content
        printf("%s", buf);

exit:
        if (buf != NULL) munmap(buf, size);
        if (fd >= 0) close(fd);
*/

}   // end cmd_cat()

////////////////////////////////////////////
static void cmd_cd( int argc , char **argv )
{
        char * path;

        if (argc != 2)
    {
                printf("usage: cd pathname\n");
                return;
        }

        path = argv[1];

    printf("error: not implemented yet\n");
/*
        path = argv[1];

        if (chdir(path) == -1) 
    {
                printf("error: cannot cd to %s\n", path);
        }
*/

}   // end cmd_cd()

/////////////////////////////////////////
static void cmd_cp(int argc, char **argv)
{
//      int src_fd = -1, dst_fd = -1;
//      char *srcpath, *dstpath;
//      struct stat st;
//      size_t size, i;
//      char buf[1024];

        if (argc != 3) 
    {
                printf("usage: cp src_pathname dst_pathname\n");
                return;
        }

    printf("error: not implemented yet\n");

/*
        srcpath = argv[1];
        dstpath = argv[2];

        // open the src file 
        src_fd = open(srcpath, O_RDONLY, 0);
        if (src_fd < 0) {
                printf("error: cannot open %s / err = %d\n", srcpath, errno);
                goto exit;
        }

        // get file size 
        if (stat(srcpath, &st) == -1) {
                printf("error: cannot stat %s\n", srcpath);
                goto exit;
        }
        if (S_ISDIR(st.st_mode)) {
                printf("error: %s is a directory\n", srcpath);
                goto exit;
        }
        size = st.st_size;

        // open the dst file 
        dst_fd = open(dstpath, O_CREAT|O_TRUNC|O_RDWR, 0);
        if (dst_fd < 0) {
                printf("error: cannot open %s / err = %d\n", dstpath, errno);
                goto exit;
        }
        if (stat(dstpath, &st) == -1) {
                printf("error: cannot stat %s\n", dstpath);
                goto exit;
        }
        if (S_ISDIR(st.st_mode)) {
                printf("error: %s is a directory\n", dstpath);
                goto exit;
        }

        i = 0;
        while (i < size)
        {
                size_t rlen = (size - i < 1024 ? size - i : 1024);
                size_t wlen;
                ssize_t ret;

                // read the source 
                ret = read(src_fd, buf, rlen);
                if (ret == -1) {
                        printf("error: cannot read from file %s\n", srcpath);
                        goto exit;
                }
                rlen = (size_t)ret;

                // write to the destination 
                ret = write(dst_fd, buf, rlen);
                if (ret == -1) {
                        printf("error: cannot write to file %s\n", dstpath);
                        goto exit;
                }
                wlen = (size_t)ret;

                // check 
                if (wlen != rlen) {
                        printf("error: cannot write on device\n");
                        goto exit;
                }

                i += rlen;
        }

exit:
        if (src_fd >= 0) close(src_fd);
        if (dst_fd >= 0) close(dst_fd);
*/

}   // end cmd_cp()

//////////////////////////////////////////////
static void cmd_help( int argc , char **argv )
{
        unsigned int i;

        if (argc != 1) 
    {
                printf("usage: %s\n", argv[0]);
                return;
        }

        printf("available commands:\n");
        for (i = 0 ; cmd[i].name ; i++) 
    {
                printf("\t%s\t : %s\n", cmd[i].name , cmd[i].desc);
        }
}   // end cmd_help()

//////////////////////////////////////////////
static void cmd_kill( int argc , char **argv )
{
        unsigned int pid;

        if (argc != 2) 
    {
                printf("usage: %s pid\n", argv[0]);
                return;
        }

        pid = atoi(argv[1]);

        if( kill( pid , 9 ) )   // TODO replace 9 by SIGKILL
    {
                printf("error: unable to kill process %x\n", pid );
        }
}   // end cmd_kill()

//////////////////////////////////////////////
static void cmd_load( int argc , char **argv )
{
        unsigned int   pid;
    unsigned int   error;
        char         * pathname;

        if (argc != 2) 
    {
                printf("usage: %s pathname \n", argv[0] );
                return;
        }

        pathname = argv[1];

    // fork system call
        pid = fork();

    if (pid == 0)  // it is the child process 
    {

printf("\n[KSH_DBG] process %x before exec\n", getpid() );

        // exec system call
        error = exec( pathname , NULL , NULL );

printf("\n[KSH_DBG] process %x after exec / error = %d\n", getpid() , error );

        if( error )
        {
            printf("error: new process unable to exec <%s>\n", pathname );
            // TODO exit();
        }
        } 
    else if ( pid < 0 )  // it is a failure reported to parent
    {
        printf("error: unable to fork\n");
    }
    else                 // it is a success reported to parent
    {

printf("\n[KSH_DBG] process %x created for <%s>\n", pid, pathname );

    }

}   // end cmd_load

/////////////////////////////////////////////
static void cmd_log( int argc , char **argv )
{
        unsigned int i;

        printf("--- registered commands ---\n");
        for (i = 0; i < LOG_DEPTH; i++) 
    {
                printf(" - %zu\t: %s\n", i, &log_entries[i].buf);
        }
}

////////////////////////////////////////////
static void cmd_ls( int argc , char **argv )
{
        char  * path;

//  struct dirent * file;
//  DIR *dir;

        if (argc == 1)
    {
                path = ".";
        }
    else if (argc == 2) 
    {
                path = argv[1];
        } 
    else 
    {
                printf("usage: ls [path]\n");
                return;
        }

    printf("error: not implemented yet\n");
/*
        dir = opendir( path );
        while ((file = readdir(dir)) != NULL)
        {
                printf(" %s\n", file->d_name);
        }
        closedir(dir);
*/
}

///////////////////////////////////////////////
static void cmd_mkdir( int argc , char **argv )
{
        char * pathname;

        if (argc != 2)
    {
                printf("usage: mkdir pathname\n");
                return;
        }

    pathname = argv[1];

    printf("error: not implemented yet\n");
/*
        if ( mkdir( path, 0x700) == -1 )
    {
                printf("error: cannot create directory %s\n", path);
        }
*/
}

////////////////////////////////////////////
static void cmd_mv( int argc , char **argv )
{

        if (argc < 3)
        {
                printf("  usage : %s src_pathname dst_pathname\n", argv[0]);
                return;
        }

    printf("error: not implemented yet\n");
    
/*
        int ret = giet_fat_rename(argv[1], argv[2]);
        if (ret < 0)
        {
                printf("error : cannot move %s to %s / err = %d\n", argv[1], argv[2], ret );
        }
*/

}

/////////////////////////////////////////////
static void cmd_pwd( int argc , char **argv )
{
        char buf[1024];

        if (argc != 1)
    {
                printf("usage: pwd\n");
                return;
        }

        if ( getcwd( buf , 1024 ) ) 
    {
                printf("error: unable to get current directory\n");
        }
    else 
    {
                printf("%s\n", buf);
        }
}

////////////////////////////////////////////
static void cmd_rm( int argc , char **argv )
{
        char * pathname;

        if (argc != 2)
    {
                printf("usage: rm pathname\n");
                return;
        }

        pathname = argv[1];

    printf("error: not implemented yet\n");
/*
        if (remove(path) == -1)
    {
                printf("error: cannot remove %s\n", path);
        }
*/

}

///////////////////////////////////////////////
static void cmd_rmdir( int argc , char **argv )
{
        cmd_rm(argc, argv);
}

///////////////////////////////////////////////
static void cmd_sched( int argc , char **argv )
{
    unsigned int cxy;
    unsigned int lid;

        if (argc != 3)
    {
                printf("usage: sched cxy lid\n");
                return;
        }

        cxy = atoi(argv[1]);
        lid = atoi(argv[2]);

    if( get_sched( cxy , lid ) )
    {
        printf("error: illegal arguments\n");
    }
}

//////////////////////////////////////////////////////////////////
// Array of commands
//////////////////////////////////////////////////////////////////

ksh_cmd_t cmd[] =
{
        { "cat",    "display file content",                cmd_cat   },
        { "cd",     "change current directory",            cmd_cd    },
        { "cp",     "replicate a file in file system",     cmd_cp    },
        { "load",   "load an user application",            cmd_load  },
        { "help",   "list available commands",             cmd_help  },
        { "kill",   "kill an application (all threads)",   cmd_kill  },
        { "log",    "list registered commands",            cmd_log   },
        { "ls",     "list directory entries",              cmd_ls    },
        { "mkdir",  "create a new directory",              cmd_mkdir },
        { "mv",     "move a file in file system",          cmd_mv    },
        { "pwd",    "print current working directory",     cmd_pwd   },
        { "rm",     "remove a file from file system",      cmd_rm    },
        { "rmdir",  "remove a directory from file system", cmd_rmdir },
    { "sched",  "display scheduler state",             cmd_sched },
        { NULL,     NULL,                                                                  NULL      }
};

////////////////////////////////////////////////////////////////////////////////////
// This function analyses one command (with arguments), execute it, and return.
////////////////////////////////////////////////////////////////////////////////////
static void parse(char *buf)
{
        int argc = 0;
        char *argv[MAX_ARGS];
        int i;
        int len = strlen(buf);

        // build argc/argv
        for (i = 0; i < len; i++) 
    {
                if (buf[i] == ' ') 
        {
                        buf[i] = '\0';
                }
        else if (i == 0 || buf[i - 1] == '\0') 
        {
                        if (argc < MAX_ARGS) 
            {
                                argv[argc] = &buf[i];
                                argc++;
                        }
                }
        }

        if (argc > 0)
    {
                int found = 0;

                argv[argc] = NULL;

                // try to match typed command 
                for (i = 0; cmd[i].name; i++)
        {
                        if (strcmp(argv[0], cmd[i].name) == 0)
            {
                                cmd[i].fn(argc, argv);
                                found = 1;
                                break;
                        }
                }

                if (!found)
        {
                        printf("\n  undefined command %s\n", argv[0]);
                }
        }
}

///////////////////////////////////
int main( int argc , char *argv[] )
{
        char         c;                                           // read character
        char         buf[CMD_MAX_SIZE];           // buffer for one command
        unsigned int count = 0;                           // pointer in buf
        unsigned int i;                                           // index for loops

        enum fsm_states 
    {
                NORMAL,
                ESCAPE,
                BRAKET,
        };

    // log buffer initialisation
        memset( &log_entries , 0, sizeof(log_entries));
        ptw   = 0;
        ptr   = 0;

        printf( "~~~ shell ~~~\n\n" );

        // command buffer initialisation
        memset( buf, 0x20 , sizeof(buf) );
        count = 0;

        // display first prompt
        printf("# ");

        // This lexical analyser writes one command line in the buf buffer.
        // It is implemented as a 3 states FSM to handle the following sequences:
        // - ESC [ A : up arrow
        // - ESC [ B : down arrow
        // - ESC [ C : right arrow
        // - ESC [ D : left arrow
        // The three states have the following semantic:
        // - NORMAL : no (ESC) character has been found
        // - ESCAPE : the character (ESC) has been found
        // - BRAKET : the wo characters (ESC,[) have been found
        unsigned int state = NORMAL;

// @@@
parse("load /bin/user/sort.elf");
// @@@
    
        while (1)
        {
                c = (char)getchar();

        if( c == 0 ) continue;

                switch (state)
                {
                        case NORMAL:
                        {
                                if ((c == '\b') || (c == 0x7F))  // backspace => remove one character
                                {
                                        if (count > 0) {
                                                printf("\b \b");
                                                count--;
                                        }
                                }
                                else if (c == '\n')      // new line => call parser to execute command
                                {
                                        if (count > 0)
                                        {
                                                // complete command
                                                buf[count] = '\0';

                                                // register command in log arrays
                                                strcpy(log_entries[ptw].buf, buf);
                                                log_entries[ptw].count = count;
                                                ptw = (ptw + 1) % LOG_DEPTH;
                                                ptr = ptw;

                                                // execute command
                                                printf("\n");
                                                parse((char *)&buf);

                                                // reinitialise buffer and display prompt
                                                for ( i = 0 ; i < sizeof(buf) ; i++ ) buf[i] = 0x20;
                                                count = 0;
                                                printf("# ");
                                        }
                                }
                                else if (c == '\t')     // tabulation => do nothing
                                {
                                }
                                else if (c == 0x1B)     // ESC => start an escape sequence
                                {
                                        state = ESCAPE;
                                }
                                else if (c == 0x03)     // ^C  => cancel current command
                                {
                                        for (i = 0; i < count; i++) printf("\b \b");
                                        for (i = 0; i < sizeof(buf); i++) buf[i] = 0x20;
                                        count = 0;
                                }
                                else                                     // register character in command buffer
                                {
                                        if (count < sizeof(buf) - 1)
                                        {
                                                printf("%c", c);
                                                buf[count] = c;
                                                count++;
                                        }
                                }
                                break;
                        }
                        case ESCAPE:
                        {
                                if (c == '[')           //  valid sequence => continue
                                {
                                        state = BRAKET;
                                }
                                else                               // invalid sequence => do nothing
                                {
                                        state = NORMAL;
                                }
                                break;
                        }
                        case BRAKET:
                        {
                                if (c == 'D')   // valid  LEFT sequence => move buf pointer left
                                {
                                        if (count > 0)
                                        {
                                                printf("\b");
                                                count--;
                                        }

                                        // get next user char
                                        state = NORMAL;
                                }
                                else if (c == 'C')   // valid  RIGHT sequence => move buf pointer right
                                {
                                        if (count < sizeof(buf) - 1)
                                        {
                                                printf("%c", buf[count]);
                                                count++;
                                        }

                                        // get next user char
                                        state = NORMAL;
                                }
                                else if (c == 'A')   // valid  UP sequence => move log pointer backward
                                {
                                        // cancel current command
                                        for (i = 0; i < count; i++) printf("\b \b");
                                        count = 0;

                                        // copy log command into buf
                                        ptr = (ptr - 1) % LOG_DEPTH;
                                        strcpy(buf, log_entries[ptr].buf);
                                        count = log_entries[ptr].count;

                                        // display log command
                                        printf("%s", buf);

                                        // get next user char
                                        state = NORMAL;
                                }
                                else if (c == 'B')   // valid  DOWN sequence => move log pointer forward
                                {
                                        // cancel current command
                                        for (i = 0 ; i < count; i++) printf("\b \b");
                                        count = 0;

                                        // copy log command into buf
                                        ptr = (ptr + 1) % LOG_DEPTH;
                                        strcpy(buf, log_entries[ptr].buf);
                                        count = log_entries[ptr].count;

                                        // display log command
                                        printf("%s", buf);

                                        // get next user char
                                        state = NORMAL;
                                }
                                else                               // other character => do nothing
                                {
                                        // get next user char
                                        state = NORMAL;
                                }
                                break;
                        }
                }
        }
}