//ww:run-exit 45
// Migrated from 777_fmt_handle_run row branched_fprintf.
package main;
import os;
import fmt;
import io;
export fn main() i32 = {
    let path: str = "wwfmth_777_d";
    let fd: i32 = os.open(path, os.flag.RDWR | os.flag.CREATE | os.flag.TRUNC, 0o644: i32);
    if (fd < 0) { return 90; };
    let sel: i32 = 1;
    let f1: str = "A{}";
    let f2: str = "B{}";
    let fmtstr: str = f1;
    if (sel == 0) { fmtstr = f2; };
    let wr = fmt.fprintf(fd: io.file, fmtstr, 9i64);
    let nw: size = 0;
    match (wr) {
    case let n: size => { nw = n; };
    case io.error => { return 91; };
    };
    os.close(fd);
    let rd: i32 = os.open(path, os.flag.RDONLY, 0i32);
    if (rd < 0) { return 92; };
    let buf: [8]u8;
    let n: i64 = os.read(rd, &buf[0], 8u64);
    os.close(rd);
    if (n != 2i64) { return 93; };
    if (nw != 2: size) { return 94; };
    if (buf[0] != 65u8 || buf[1] != 57u8) { return 95; };
    return 45;
};