format.c

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/*
 * (c) copyright 1987 by the Vrije Universiteit, Amsterdam, The Netherlands.
 * See the copyright notice in the ACK home directory, in the file "Copyright".
 */
/* $Header: /opt/proj/minix/cvsroot/src/commands/aal/format.c,v 1.1.1.1 2005/04/21 14:53:57 beng Exp $ */

#if __STDC__
#include <stdarg.h>
#else
#include <varargs.h>
#endif

extern char *long2str();

static int
integral(c)
{
        switch (c) {
        case 'b':
                return -2;
        case 'd':
                return 10;
        case 'o':
                return -8;
        case 'u':
                return -10;
        case 'x':
                return -16;
        }
        return 0;
}

/*VARARGS2*/
/*FORMAT1 $
        %s = char *
        %l = long
        %c = int
        %[uxbo] = unsigned int
        %d = int
$ */
int
_format(buf, fmt, argp)
        char *buf, *fmt;
        register va_list argp;
{
        register char *pf = fmt;
        register char *pb = buf;

        while (*pf) {
                if (*pf == '%') {
                        register width, base, pad, npad;
                        char *arg;
                        char cbuf[2];
                        char *badformat = "<bad format>";
                        
                        /* get padder */
                        if (*++pf == '0') {
                                pad = '0';
                                ++pf;
                        }
                        else
                                pad = ' ';
                        
                        /* get width */
                        width = 0;
                        while (*pf >= '0' && *pf <= '9')
                                width = 10 * width + *pf++ - '0';
                        
                        if (*pf == 's') {
                                arg = va_arg(argp, char *);
                        }
                        else
                        if (*pf == 'c') {
                                cbuf[0] = va_arg(argp, int);
                                cbuf[1] = '\0';
                                arg = &cbuf[0];
                        }
                        else
                        if (*pf == 'l') {
                                /* alignment ??? */
                                if (base = integral(*++pf)) {
                                        arg = long2str(va_arg(argp,long), base);
                                }
                                else {
                                        pf--;
                                        arg = badformat;
                                }
                        }
                        else
                        if (base = integral(*pf)) {
                                arg = long2str((long)va_arg(argp,int), base);
                        }
                        else
                        if (*pf == '%')
                                arg = "%";
                        else
                                arg = badformat;

                        npad = width - strlen(arg);

                        while (npad-- > 0)
                                *pb++ = pad;
                        
                        while (*pb++ = *arg++);
                        pb--;
                        pf++;
                }
                else
                        *pb++ = *pf++;
        }
        return pb - buf;
}

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