open3_at.c (1130B)
1 /* ISC license. */ 2 3 #include <skalibs/sysdeps.h> 4 5 #ifdef SKALIBS_HASOPENAT 6 7 #ifndef _ATFILE_SOURCE 8 #define _ATFILE_SOURCE 9 #endif 10 11 #include <skalibs/nonposix.h> 12 13 #include <errno.h> 14 15 #include <skalibs/fcntl.h> 16 #include <skalibs/unix-transactional.h> 17 18 int open3_at (int dirfd, char const *file, int flags, unsigned int mode) 19 { 20 int fd ; 21 do fd = openat(dirfd, file, flags, mode) ; /* all systems that support openat() have O_CLOEXEC */ 22 while (fd == -1 && errno == EINTR) ; 23 return fd ; 24 } 25 26 #else 27 28 #include <sys/stat.h> 29 #include <errno.h> 30 31 #include <skalibs/fcntl.h> 32 #include <skalibs/djbunix.h> 33 #include <skalibs/unix-transactional.h> 34 35 int open3_at (int dirfd, char const *file, int flags, unsigned int mode) 36 { 37 int fd ; 38 int fdhere = open_read(".") ; 39 if (fdhere < 0) return -1 ; 40 if (fd_chdir(dirfd) < 0) goto errclose ; 41 fd = open3(file, flags, mode) ; 42 if (fd < 0) 43 { 44 int e = errno ; 45 fd_chdir(fdhere) ; 46 errno = e ; 47 goto errclose ; 48 } 49 if (fd_chdir(fdhere) < 0) 50 { 51 fd_close(fd) ; 52 goto errclose ; 53 } 54 fd_close(fdhere) ; 55 return fd ; 56 57 errclose: 58 fd_close(fdhere) ; 59 return -1 ; 60 } 61 62 #endif