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32 .Nd "Reliably open and lock a file"
39 .Fn flopen "const char *path" "int flags"
41 .Fn flopen "const char *path" "int flags" "mode_t mode"
43 .Fn flopenat "int fd" "const char *path" "int flags"
45 .Fn flopenat "int fd" "const char *path" "int flags" "mode_t mode"
49 function opens or creates a file and acquires an exclusive lock on it.
50 It is essentially equivalent with calling
52 with the same parameters followed by
60 will attempt to detect and handle races that may occur between opening
61 / creating the file and locking it.
62 Thus, it is well suited for opening lock files, PID files, spool
63 files, mailboxes and other kinds of files which are used for
64 synchronization between processes.
70 and the file is already locked,
81 argument is required if
88 function is equivalent to the
90 function except in the case where the
92 specifies a relative path.
93 In this case the file to be opened is determined relative to the directory
94 associated with the file descriptor
96 instead of the current working directory.
99 is passed the special value
103 parameter, the current working directory is used
104 and the behavior is identical to a call to
109 returns a valid file descriptor.
110 Otherwise, it returns -1, and sets
124 function and this manual page were written by
125 .An Dag-Erling Sm\(/orgrav Aq Mt des@FreeBSD.org .