i have problem with these program

[southparkcab]

# include <stdio.h>
# include <stdlib.h>
# include <math.h>
# define M_SQRT
/* macro to insert blank lines on screen */
#define BLANK_LINE(n) {int i=0;for(i<(n);i++)fprintf(stderr,"\n";}
 
void print_message(void);
void fpos(FILE*outfile,float a,float b,float c,float d);
void fzero(FILE*outfile,float a,float b,float c,float d);
void fneg(FLIE*outfile,float a,float b,float c,float d);
 
int main(void){
    int comp;
    float a, b, c, d, x1,x2;
    FILE *infile, *outfile;
 
    infile=fopen("abc.txt","r");
    outfile=fopen("roots207.txt,"w"); 
 print_message();
 
    while(EOF !=fscanf(infile,"%f%f%f",&a,&b,&c)){
 
    d = b*b-4*a*c;
 
    ax^2 + bx +c = 0 ;
 
    x1 = (-b + sqrt(b*b - 4ac)) / 2a);
    x2 = (-b - sqrt(b*2 - 4ac)) / 2a);
 
    if(a==0 && b==0 && c==0)
        code = 1;
    else if(a==O && b!=0 && c==0)
        code = 2; 
    else if(a==0 && b!=0 && c!=0)
        code = 3;
    else if(a>0 && d==0)
        code = 4;
 else if(a<0 && d==0)
        code = 5;
    else if(a!=0 && d<0)
        code = 6;
  switch(code) {
    code 1:
        root1(outfile,a,b,c);
        break;   
    code 2:
        root2(outfile,a,b,c);
  break;
    code 3:
        root3(outfile,a,b,c);
        break;   
   code 4:
        root4(outfile,a,b,c);
        break;
    code 5:
        root5(outfile,a,b,c);
        break;
code 6:
        root6(outfile,a,b,c);
        break;
    default:
        puts("ERROR1: Never get here!");
    }/* end switch-case */
}/* end while() */
    fclose(infile);
    fclose(outfile);
    return;
/*----------------function definitions---------------------- */
void print_message(void){
  BLANK_LINES(16)
/* the following sends output to screen even when output redirected */
fprintf(stderr,
    "--------------------------------------------------------\n"
                                "INPUT: from file abc.txt\n"
                                "OUTPUT: to file roots207.txt\n"
                                "Each row must contain three real numbers.\n"
                                "Program terminates when end-of-file is reached$
   "---------------------------------------------------\n"
);
  BLANK_LINES(16);
return;
}
void root1(FILE* outfile,double a,double b,double c,double d,double x1,double x2){
    fputs("--------------------------------------------\n", outfile);
    fprintf(outfile,"(a,b,c) = (%4.1f,%4.1f,%4.1f), %fx^2+%fx+%f=0=%8.4f, \n",a
    fprintf(outfile,"has an an infinity of roots: all complex numbers are roots$
 

i just start doing C so this is as far as i can go can any1 so me what to do next so my program can work
thx

[enri]

There are some syntax errors and some calls to non-existent functions.

You should check that all constant strings you would like to print with fprintf are enclosed in quotes:
fprintf(stderr,"This is an error );
fprintf(stderr,"This is correct");

and you should also check that all brackets are matched: whenever you open a bracket there must be the correponding closing one:
fprintf(stderr,"\n"; // this is an error
fprintf(stderr,"\n"); //this is correct

The for statement takes three parameters: for(initial condition; expression1; expression2), so that the correct syntax will be:
for(int i=0;i<n;i++) fprintf(stderr,"\n");

You can also omit some parameters, by leaving blank their position
int i=0; for( ;i<n;i++) fprintf(stderr,"\n");

In the switch statement, you should not repeat for each case the variable which you are checking the value for. Instead you should write a "case" keyword followed by the value tha variable is checked against:
switch(code)
{
case 1: //code for the case code=1
break;
case 2: //code for the case code=2
break;
default: //code for the default case
}

Finally, you are using the function root1 before having defined it. You should place its prototype together with those of the other functions(fpos, fzero, fneg and print_message), so that the "main" knows of its existence. The same goes with the other functions root2, ... ,root6, that have never been defined.

Hope this will help.