ref: b9745c60a1bf2a3876e411d38c67a0980d70e3a3
dir: /sys/src/ape/lib/ap/plan9/dup.c/
#include "lib.h" #include <unistd.h> #include <errno.h> int dup(int oldd) { return fcntl(oldd, F_DUPFD, 0); } int dup2(int oldd, int newd) { if(newd < 0 || newd >= OPEN_MAX){ errno = EBADF; return -1; } if(oldd == newd && _fdinfo[newd].flags&FD_ISOPEN) return newd; close(newd); return fcntl(oldd, F_DUPFD, newd); }