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34 .Nd "Reliably open and lock a file"
41 .Fn flopen "const char *path" "int flags"
43 .Fn flopen "const char *path" "int flags" "mode_t mode"
45 .Fn flopenat "int fd" "const char *path" "int flags"
47 .Fn flopenat "int fd" "const char *path" "int flags" "mode_t mode"
51 function opens or creates a file and acquires an exclusive lock on it.
52 It is essentially equivalent with calling
54 with the same parameters followed by
62 will attempt to detect and handle races that may occur between opening
63 / creating the file and locking it.
64 Thus, it is well suited for opening lock files, PID files, spool
65 files, mailboxes and other kinds of files which are used for
66 synchronization between processes.
72 and the file is already locked,
83 argument is required if
90 function is equivalent to the
92 function except in the case where the
94 specifies a relative path.
95 In this case the file to be opened is determined relative to the directory
96 associated with the file descriptor
98 instead of the current working directory.
101 is passed the special value
105 parameter, the current working directory is used
106 and the behavior is identical to a call to
111 returns a valid file descriptor.
112 Otherwise, it returns -1, and sets
126 function and this manual page were written by
127 .An Dag-Erling Sm\(/orgrav Aq Mt des@FreeBSD.org .