K+R Exercise7_3

/* Revise minprintf() to handle more of the other facilities of printf()
   implemented ( %d  %5d  %-5d  %.2f  %1.2g  %-3.4s )

%*d %.*d etc unimplemented.

   too many args causes a segmentation error instead of an error message.
   try-except not implemented

     just ignores rogue %'s if included  "frog % lemo"
-2233 % -2233-
-2233  -2233-
    this normally produces an exception

-2233 %roggy-stuff -2233-
-2233 roggy-stuff -2233-


# in Python it skips blanks and formats with the first letter found

print "froggy % stuff %d" % ("tree",3)
froggy treetuff 3

>>> print "froggy % muff %d" % ("tree",3)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ValueError: unsupported format character 'm' (0x6d) at index 9


*/

#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>  /* va_list and args */

#define MAXTOKEN 1000

int minprintf(char *fmt, ...);  /* '...' - accept all the args after fmt */
char * makeStr(char *m, char c, int ia1, int dpoi, int dpoi2, int iarg, int jarg);

#define maketh makeStr(mstr, type, ia1, dpoi, dpoi2, iarg, jarg) /* macro */

main()
{
    int i = 69;
    float j = 0.000232;
    char k[]="frog";
    char *m = &k[0];

    minprintf("There %   -2.1c %% %12.4f -2233 -2233- .. *** was %-10.2s at %12p\n",i,j,k,m);

    return 0;
}

/* minprintf: minimal printf with variable arguement list */
int minprintf(char *fmt, ...)
{
    va_list ap;          /* points to each unnamed arg in turn  */
    char mstr[MAXTOKEN]; /* make string in outside function     */
    char *p, *sval, *temp1;
    int ival, type, iarg=0, ia1=0, jarg=0, dpoi=0, dpoi2=0, ineg;
    double dval;
    void *pval;

    va_start(ap, fmt);   /* make ap point to the 1st unnamed arg */
    for(p=fmt; *p; p++) {
        if(*p != '%') {
            putchar(*p);
            continue;
        }
        type = *++p;
        while(type==' ')  /* Default behaviour seems to be to skip spaces */
            type = *++p;  /* and match with the first chars found after   */
        if(type=='-') {
            ineg=1;
            type = *++p;
        } if(type=='-') {
            puts("\nerror: invalid formatting '%--'");
            return -1;
        } if(type=='.') {
            if(ineg) {
                puts("\nerror: invalid formatting '-.'");
                return -1;
            }
            dpoi = 1;
            type = *++p;
        } if(isdigit(type)) {
            iarg = atoi(p);
            ia1 = 1;
            while(isdigit(*++p))
                ;
            if(ineg) {
               iarg-=(iarg*2);
               ineg = 0;
            } type = *p;
        } if(type=='.') {
            if(dpoi) {
                puts("\nerror: invalid formatting '.XX.'");
                return -1;
            }
            dpoi2 = 1;
            type = *++p;
        } if(isdigit(type)) {
            jarg = atoi(p);
            ia1 = 1;
            while(isdigit(*++p))
                ;
            type = *p;
        } if(type=='.') {
                puts("\nerror: invalid formatting '.X.X.'");
                return -1;
        }
        switch(type) {
            case '%':
                printf("%%");
                break;
            case 'd':
                ival = va_arg(ap, int);
                temp1 = maketh;
                printf(temp1,ival);
                break;
            case 'i':
                ival = va_arg(ap, int);
                temp1 = maketh;
                printf(temp1,ival);
                break;
            case 'o':
                ival = va_arg(ap, int);
                temp1 = maketh;
                printf(temp1,ival);
                break;
            case 'x':
                ival = va_arg(ap, int);
                temp1 = maketh;
                printf(temp1,ival);
                break;
            case 'X':
                ival = va_arg(ap, int);
                temp1 = maketh;
                printf(temp1,ival);
                break;
            case 'u':
                ival = va_arg(ap, int);
                temp1 = maketh;
                printf(temp1,ival);
                break;
            case 'c':
                ival = va_arg(ap, int);
                temp1 = maketh;
                printf(temp1,ival);
                break;
            case 'f':
                dval = va_arg(ap, double);
                temp1 = maketh;
                printf(temp1,dval);
                break;
            case 'e':
                dval = va_arg(ap, double);
                temp1 = maketh;
                printf(temp1,dval);
                break;
            case 'E':
                dval = va_arg(ap, double);
                temp1 = maketh;
                printf(temp1,dval);
                break;
            case 'g':
                dval = va_arg(ap, double);
                temp1 = maketh;
                printf(temp1,dval);
                break;
            case 'G':
                dval = va_arg(ap, double);
                temp1 = maketh;
                printf(temp1,dval);
                break;
            case 's':
                if(!ia1) {
                    for(sval = va_arg(ap, char *); *sval; sval++)
                        putchar(*sval);
                    break;
                }
                else {
                    sval = va_arg(ap, char *);
                    temp1 = maketh;
                    printf(temp1,sval);
                    for( ; *sval; sval++) /* pass the rest of the string away */
                        ;
                    break;
                }
            case 'p':
                pval = va_arg(ap, void *);
                temp1 = maketh;
                printf(temp1,pval);
                break;
            default:
                putchar(*p);
                break;
            }
            ia1   = 0;  /* flag that num args are being used    */
            iarg  = 0;
            jarg  = 0;
            dpoi  = 0;  /* flags that decimal point is included */
            dpoi2 = 0;  /*   "    "     "       "    "    "     */
        }
        va_end(ap);     /* clean up when done                   */
}

/* makeStr: create and return the formatting string */
char * makeStr(char *m, char c, int ia1, int dpoi, int dpoi2, int iarg, int jarg)
{
    int i=0;
    char res[MAXTOKEN];

    if(!ia1) {
        char f[] = "%%c", c;            /* e.g., %f     */
        sprintf(m,f,c);
    } else {
        if(!dpoi && !dpoi2) {           /* e.g., %3f    */
            char f[] = "%%%c";
            sprintf(m,f,c);
        } else if(dpoi){
            char f[] = "%%%%.%%d%c";    /* e.g., %.3f   */
            sprintf(res,f,c);
            sprintf(m,res,iarg);
        } else {
            char f[] = "%%%%%%d.%%d%c"; /* e.g., %62.3f */
            sprintf(res,f,c);
            sprintf(m,res,iarg,jarg);
        }
    }
    return m;
}