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31 .Nd create IPC identifier from path name
38 .Fn ftok "const char *path" "int id"
42 function attempts to create a unique key suitable for use with the
49 of an existing file and a user-selectable
54 must specify an existing file that is accessible to the calling process
55 or the call will fail.
56 Also, note that links to files will return the same key, given the same
59 Only the 8 least significant bits of
61 are used in the key generation; the rest of the bits are ignored.
65 function will return ((key_t)-1) if
67 does not exist or if it cannot be accessed by the calling process.
80 function originated with System V and is typically used by programs
81 that use the System V IPC routines.
83 .An Thorsten Lockert Aq Mt tholo@sigmasoft.com
85 The returned key is computed based on the device and inode of the
88 in combination with the given
90 Thus it is quite possible for the routine to return duplicate keys
91 given that those fields are not 8- and 16-bit quantities like they
92 were on System V based systems where this library routine's ancestor
93 were originally created.