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GNU Info (make.info)Selective SearchThe `vpath' Directive --------------------- Similar to the `VPATH' variable, but more selective, is the `vpath' directive (note lower case), which allows you to specify a search path for a particular class of file names: those that match a particular pattern. Thus you can supply certain search directories for one class of file names and other directories (or none) for other file names. There are three forms of the `vpath' directive: `vpath PATTERN DIRECTORIES' Specify the search path DIRECTORIES for file names that match PATTERN. The search path, DIRECTORIES, is a list of directories to be searched, separated by colons (semi-colons on MS-DOS and MS-Windows) or blanks, just like the search path used in the `VPATH' variable. `vpath PATTERN' Clear out the search path associated with PATTERN. `vpath' Clear all search paths previously specified with `vpath' directives. A `vpath' pattern is a string containing a `%' character. The string must match the file name of a prerequisite that is being searched for, the `%' character matching any sequence of zero or more characters (as in pattern rules; *note Defining and Redefining Pattern Rules: Pattern Rules.). For example, `%.h' matches files that end in `.h'. (If there is no `%', the pattern must match the prerequisite exactly, which is not useful very often.) `%' characters in a `vpath' directive's pattern can be quoted with preceding backslashes (`\'). Backslashes that would otherwise quote `%' characters can be quoted with more backslashes. Backslashes that quote `%' characters or other backslashes are removed from the pattern before it is compared to file names. Backslashes that are not in danger of quoting `%' characters go unmolested. When a prerequisite fails to exist in the current directory, if the PATTERN in a `vpath' directive matches the name of the prerequisite file, then the DIRECTORIES in that directive are searched just like (and before) the directories in the `VPATH' variable. For example, vpath %.h ../headers tells `make' to look for any prerequisite whose name ends in `.h' in the directory `../headers' if the file is not found in the current directory. If several `vpath' patterns match the prerequisite file's name, then `make' processes each matching `vpath' directive one by one, searching all the directories mentioned in each directive. `make' handles multiple `vpath' directives in the order in which they appear in the makefile; multiple directives with the same pattern are independent of each other. Thus, vpath %.c foo vpath % blish vpath %.c bar will look for a file ending in `.c' in `foo', then `blish', then `bar', while vpath %.c foo:bar vpath % blish will look for a file ending in `.c' in `foo', then `bar', then `blish'. automatically generated by info2www version 1.2.2.9 |