Power-Programmierung/CD2.mdf/c/library/dos/cmdline/asmfix4/e.c

C/C++ Source or Header | 1985-12-11 | 4.2 KB | 178 lines

/*
    Execute DOS .EXE file with standard handles redirected.
    Accept redirection arguments of the form:

    e -r file command  : stdout and stderr to file. ( space opt. )
    e -r #hnd command  : stdout and stderr to handle hnd. ( space req.)
    e -rhnd file command : handle hnd to file.
    e -rhnd1 #hnd2 command : handle hnd1 to handle hnd2.

    Same as above with -a instead of -r will append.

    Standard handles are:

            0 - standard input ( not useful here )
            1 - standard output.
            2 - standard error.
            3 - standard auxillary ( usually serial port ).
            4 - standard printer ( usually parallel port ).

    Examples:

        e -r out masm test,,test;
            -- send all standard output and standard error output
               to the file 'out'.  Note that due to the
               difference in the way C stream level stdout and
               stderr are handled, 'out' may contain output in
               a different order from that seen on the screen.

        e -r2 errors masm test;
            -- send all standard error output to the file
               errors.  Standard out still goes to the
               console.

        e -r1 out -r2 errs masm test;
            -- send standard output to file 'out'.
            -- send standard error to file 'errs'.

        e -r4 #1 masm test;
            -- send printer output to console.

*/

#include <process.h>
#include <io.h>
#include <stdlib.h>
#include <fcntl.h>
#include <sys\types.h>
#include <sys\stat.h>
#include <ctype.h>
#include <string.h>

/*  Error return codes */
#define NO_ARGS    1
#define DUP    2
#define EXEC    3
#define OPEN    4
#define BAD_SWITCH    5

/*  Known handles */
#define STDOUT    1
#define STDERR    2

#define SWITCHARS    "-/"
#define DIGITS        "0123456789"
#define FALSE    0
#define TRUE    -1

int Redirect();

/*****            ************            ***********************/
main( argc, argv )
int argc;
char *argv[];
{
int argcount = 1;

    if ( argc < 2 )
    {
        puts( "Usage is: e [<-r|-a[hnd] filename|hnd>] <.EXE file> <arglist>" );
        exit( NO_ARGS );
    }

    while( strcspn( argv[argcount], SWITCHARS ) == 0 )

        argcount += Redirect( argv + argcount );

    if ( execvp( argv[argcount], argv + argcount ) == -1 )
    {
        printf( argv[argcount] );
        perror( ": Exec Error" );
        exit( EXEC );
    }
}


/*********    *********    **********    *************/
int Redirect( argv )
char *argv[];
{
char * cur = argv[0] + 1; /* Start looking at second char */
int  handle1 = -1;    /* Handle directed from */
int  handle2 = -1;    /* Handle directed to */
int  append = FALSE;    /* Append to output file? */
int  numargs = 2;    /* Number of command line arguments used */
int  index;        /* Used for distinguishing cases */


    switch ( *cur )
    {
        case 'a' : append = TRUE;
        case 'r' : cur++;
               break;
        default  : printf( "Mal-formed switch: '%s'\n", cur - 1 );
               exit( BAD_SWITCH );
    }
    index = strspn( cur, DIGITS ); /* Find first non-digit */
    if ( cur[ index ] == '\0'  &&  index ) /* If it's end-of-string, and
                          string len > 1, then we're
                          looking at -r# filename */
    {
        if ( !sscanf( cur, "%d" , &handle1 ) )
        {
            printf( "Bad handle in switch expression: '%s'\n",
                cur );
            exit( BAD_SWITCH );
        }
        cur = argv[1];
    }
    else { /* If first char is nul, we're looking at -r filename */
        if ( *cur == '\0' ) cur = argv[1];
        else    numargs = 1; /* Else we're looking at -rfilename */
        }


    if ( *cur == '#' )  /* handle2 is in command string */
    {
        if ( !sscanf( cur + 1, "%d", &handle2 ) )
        {
            printf( "Bad handle in switch expression: '%s'",
                cur + 1 );
            exit( BAD_SWITCH );
        }
    }
    else    /* handle2 must be generated with open() */
        if ( (handle2 = open( cur ,
              O_WRONLY | (append ? O_APPEND : O_TRUNC ) | O_CREAT,
              S_IWRITE )) == -1 )
        {
            printf( cur );
            perror( ": Open Error" );
            exit( OPEN );
        }

    if ( !(handle1 == -1) ) /* Handle to redirect is specified */
    {
        if ( dup2( handle2, handle1 ) == -1 )
        {
            perror( "Dup2 Error" );
            exit( DUP );
        }
    }
    else
    {
        if ( dup2( handle2, STDOUT ) == -1 )
        {
            perror( "Dup2 Error on Standard Out" );
            exit( DUP );
        }
        if ( dup2( handle2, STDERR ) == -1 )
        {
            perror( "Dup2 Error on Standard Error" );
            exit( DUP );
        }
    }

    return numargs;
}