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- /*
- * 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;
- }
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