The result is a Number, which is |TRUE| if a buffer called {expr} exists. If the {expr} argument is a number, buffer numbers are used. Number zero is the alternate buffer for the current window.

If the {expr} argument is a string it must match a buffer name exactly. The name can be:

• Relative to the current directory.
• A full path.
• The name of a buffer with 'buftype' set to "nofile".
• A URL name. Unlisted buffers will be found. Note that help files are listed by their short name in the output of |:buffers|, but bufexists() requires using their long name to be able to find them. bufexists() may report a buffer exists, but to use the name with a |:buffer| command you may need to use |expand()|. Esp for MS-Windows 8.3 names in the form "c:\DOCUME~1" Use "bufexists(0)" to test for the existence of an alternate file name.