initial import

lib9/open.c

@@ -0,0 +1,62 @@
+#define _GNU_SOURCE	/* for Linux O_DIRECT */
+#include <u.h>
+#define NOPLAN9DEFINES
+#include <sys/file.h>
+#include <libc.h>
+#ifndef O_DIRECT
+#define O_DIRECT 0
+#endif
+
+int
+p9open(char *name, int mode)
+{
+	int cexec, rclose;
+	int fd, umode, lock, rdwr;
+	struct flock fl;
+
+	rdwr = mode&3;
+	umode = rdwr;
+	cexec = mode&OCEXEC;
+	rclose = mode&ORCLOSE;
+	lock = mode&OLOCK;
+	mode &= ~(3|OCEXEC|ORCLOSE|OLOCK);
+	if(mode&OTRUNC){
+		umode |= O_TRUNC;
+		mode ^= OTRUNC;
+	}
+	if(mode&ODIRECT){
+		umode |= O_DIRECT;
+		mode ^= ODIRECT;
+	}
+	if(mode&ONONBLOCK){
+		umode |= O_NONBLOCK;
+		mode ^= ONONBLOCK;
+	}
+	if(mode&OAPPEND){
+		umode |= O_APPEND;
+		mode ^= OAPPEND;
+	}
+	if(mode){
+		werrstr("mode 0x%x not supported", mode);
+		return -1;
+	}
+	fd = open(name, umode);
+	if(fd >= 0){
+		if(lock){
+			fl.l_type = (rdwr==OREAD) ? F_RDLCK : F_WRLCK;
+			fl.l_whence = SEEK_SET;
+			fl.l_start = 0;
+			fl.l_len = 0;
+			if(fcntl(fd, F_SETLK, &fl) < 0){
+				close(fd);
+				werrstr("lock: %r");
+				return -1;
+			}
+		}
+		if(cexec)
+			fcntl(fd, F_SETFL, FD_CLOEXEC);
+		if(rclose)
+			remove(name);
+	}
+	return fd;
+}