diff options
-rw-r--r-- | lib/libc/sys/open.2 | 20 |
1 files changed, 12 insertions, 8 deletions
diff --git a/lib/libc/sys/open.2 b/lib/libc/sys/open.2 index 1a29a17..d62a4b6 100644 --- a/lib/libc/sys/open.2 +++ b/lib/libc/sys/open.2 @@ -57,7 +57,8 @@ The argument may indicate the file is to be created if it does not exist (by specifying the .Dv O_CREAT -flag). In this case +flag). +In this case .Nm requires a third argument .Fa "mode_t mode" , @@ -91,7 +92,8 @@ O_NOFOLLOW do not follow symlinks Opening a file with .Dv O_APPEND set causes each write on the file -to be appended to the end. If +to be appended to the end. +If .Dv O_TRUNC is specified and the file exists, the file is truncated to zero length. @@ -102,7 +104,8 @@ is set with and the file already exists, .Fn open -returns an error. This may be used to +returns an error. +This may be used to implement a simple exclusive access locking mechanism. If .Dv O_EXCL @@ -151,11 +154,12 @@ If creating a file with the request for the lock will never fail (provided that the underlying filesystem supports locking). .Pp -.Dv O_DIRECT may be used to -minimize or eliminate the cache effects of reading and writing. The system -will attempt to avoid caching the data you read or write. If it cannot -avoid caching the data, it will minimize the impact the data has on the cache. -Use of this flag can drastically reduce performance if not used with care. +.Dv O_DIRECT +may be used to minimize or eliminate the cache effects of reading and writing. +The system will attempt to avoid caching the data you read or write. +If it cannot avoid caching the data, +it will minimize the impact the data has on the cache. +Use of this flag can drastically reduce performance if not used with care. .Pp If successful, .Fn open |