Subversion Repositories planix.SVN

/*
 * pANS stdio -- freopen
 */
#include "iolib.h"
/*
 * Open the named file with the given mode, using the given FILE
 * Legal modes are given below, `additional characters may follow these sequences':
 * r rb         open to read
 * w wb         open to write, truncating
 * a ab         open to write positioned at eof, creating if non-existant
 * r+ r+b rb+   open to read and write, creating if non-existant
 * w+ w+b wb+   open to read and write, truncating
 * a+ a+b ab+   open to read and write, positioned at eof, creating if non-existant.
 */
FILE *freopen(const char *name, const char *mode, FILE *f){
        int m;

        if(f->state!=CLOSED){
                fclose(f);
/* premature; fall through and see what happens */
/*              f->state=OPEN; */
        }

        m = *mode++;
        if(m == 0)
                return NULL;
        if(*mode == 'b')
                mode++;
        switch(m){
        default:
                return NULL;
        case 'r':
                f->fd=open(name, (*mode == '+'? ORDWR: OREAD));
                break;
        case 'w':
                f->fd=create(name, (*mode == '+'? ORDWR: OWRITE), 0666);
                break;
        case 'a':
                m = (*mode == '+'? ORDWR: OWRITE);
                f->fd=open(name, m);
                if(f->fd<0)
                        f->fd=create(name, m, 0666);
                seek(f->fd, 0LL, 2);
                break;
        }

        if(f->fd==-1)
                return NULL;
        f->flags=(mode[0]=='a')? APPEND : 0;
        f->state=OPEN;
        f->buf=0;
        f->rp=0;
        f->wp=0;
        f->lp=0;
        return f;
}