Q45187: Documented Search Order for Include Files

Article: Q45187
Product(s): See article
Version(s): 5.00 5.10 | 5.10
Operating System(s): MS-DOS | OS/2
Keyword(s): ENDUSER | docerr | mspl13_c
Last Modified: 18-SEP-1989

I am having trouble determining the precise search order for include
files. The Version 5.10 "Microsoft C for the MS-DOS Operating System:
User's Guide" states the following on Page 34:

   The compiler always searches the current working directory first
   before searching the locations given in the environment variable.

(Except when using < >).

The Version 5.10 "Microsoft C for the MS-DOS Operating System:
Language Reference" on Page 203 discusses searching in terms of the
"parent" file's directory, then also mentions the current working
directory in a subsequent paragraph.

From my experimenting, it seems that all references to the current
working directory are incorrect. The compiler actually searches based
on the parent's directory. The MS-DOS current directory is never
searched unless it is included on the command line or in the INCLUDE
variable.

The above assumptions are correct. All references to the "current
working directory" should be referring to the "parent" directory. This
is a documentation error. If include files are nested, then this error
becomes important. With nested include files, the current working
directory can be very different from the parent directory. The parent
directory is always the one that is searched.

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