github.com/afumu/libc@v0.0.6/musl/src/stdio/__fmodeflags.c (about)

     1  #include <fcntl.h>
     2  #include <string.h>
     3  
     4  int __fmodeflags(const char *mode)
     5  {
     6  	int flags;
     7  	if (strchr(mode, '+')) flags = O_RDWR;
     8  	else if (*mode == 'r') flags = O_RDONLY;
     9  	else flags = O_WRONLY;
    10  	if (strchr(mode, 'x')) flags |= O_EXCL;
    11  	if (strchr(mode, 'e')) flags |= O_CLOEXEC;
    12  	if (*mode != 'r') flags |= O_CREAT;
    13  	if (*mode == 'w') flags |= O_TRUNC;
    14  	if (*mode == 'a') flags |= O_APPEND;
    15  	return flags;
    16  }