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VisionX V4 Programmers Guide

VisionX V4

Example VXparse Program for command line parameters  

The following source code is a program that illustrates the use of VXparse to parse command line parameters.

/****************************************************************/
/* Example VisionX program that demonstrates the use of VXparse */
/*      and related tools for command line argument parsing     */
/* Syntax:                                                      */
/*        vpex if=infile of=outfile                             */
/****************************************************************/
#include "VisXV4.h"
#include "Vutil.h"
             /* Every VisionX program should have       */
             /* a "par" declaration that defines the    */
             /* prefixes for the command line arguments */
             /* vparse will fill the second element of  */
             /* the structure with the address of       */
             /* any matched prefixes in the command     */

VXparam_t par[] = {      /*  command line structure                */
{   "if=",    0,         " input file name                         "},
{   "of=",    0,         " ouput file name                         "},
{   "-i",     0,         " a simple flag                           "},
{   "n=",     0,         " an integer input value                  "},
{   "s=",     0,         " a floating point input value            "},
{   "xy=",    0,         " input one or two values                 "},
{   0,        0,         0}   /* list terminator */
};
#define  IVAL   par[0].val   /* these defines give symbolic names   */
#define  OVAL   par[1].val   /* to the second element of the par    */
#define  IFLAG  par[2].val   /* structure. For example, the string  */
#define  NVAL   par[3].val   /* matched to "if=" (if it is found)   */
#define  SVAL   par[4].val   /* may be referred to in the program   */
#define  XYVAL  par[5].val   /* as IVAL                             */
extern double atof();

main(argc, argv)
int argc;
char *argv[];
{
    int n;
    float s;
    int x, y;

    VXparse(&argc, &argv, par);  /* parse the command line */

    if (IVAL)  
        (void) fprintf(stdout,  "input file name is %s\n", IVAL);
    if (OVAL)   
        (void) fprintf(stdout, "output file name is %s\n", OVAL);
    if (IFLAG) 
        (void) fprintf(stdout, "Option -i has been selected\n");
    n = 0;    /* default for n */
    if (NVAL) {
        n = atoi(NVAL);
        (void) fprintf(stdout, "n= (integer argument) is %d\n", n);
    }
    s = 0.0;  /* default for s */
    if (SVAL) {
        s = (float)atof(SVAL);
        (void) fprintf(stdout, "s= (float argument) is %f\n", s);
    }
    x = 0;    /* default for x */
    y = 0;    /* default for y */
    if (XYVAL) /* input two values */
        switch (sscanf(XYVAL, "%d,%d", &x, &y)) {
        case 2:
            break;
        case 1:
            y = x;
            break;
        default:
            (void) fprintf(stderr, "Bad input to xy=\n");
            exit(1);
    }
    exit(0);
}