(make.info.gz) Libraries/Search

Info Catalog

(make.info.gz) Implicit/Search

(make.info.gz) Directory Search

 
 4.5.6 Directory Search for Link Libraries
 -----------------------------------------
 
 Directory search applies in a special way to libraries used with the
 linker.  This special feature comes into play when you write a
 prerequisite whose name is of the form `-lNAME'.  (You can tell
 something strange is going on here because the prerequisite is normally
 the name of a file, and the _file name_ of a library generally looks
 like `libNAME.a', not like `-lNAME'.)
 
    When a prerequisite's name has the form `-lNAME', `make' handles it
 specially by searching for the file `libNAME.so' in the current
 directory, in directories specified by matching `vpath' search paths
 and the `VPATH' search path, and then in the directories `/lib',
 `/usr/lib', and `PREFIX/lib' (normally `/usr/local/lib', but
 MS-DOS/MS-Windows versions of `make' behave as if PREFIX is defined to
 be the root of the DJGPP installation tree).
 
    If that file is not found, then the file `libNAME.a' is searched
 for, in the same directories as above.
 
    For example, if there is a `/usr/lib/libcurses.a' library on your
 system (and no `/usr/lib/libcurses.so' file), then
 
      foo : foo.c -lcurses
              cc $^ -o $@
 
 would cause the command `cc foo.c /usr/lib/libcurses.a -o foo' to be
 executed when `foo' is older than `foo.c' or than
 `/usr/lib/libcurses.a'.
 
    Although the default set of files to be searched for is `libNAME.so'
 and `libNAME.a', this is customizable via the `.LIBPATTERNS' variable.
 Each word in the value of this variable is a pattern string.  When a
 prerequisite like `-lNAME' is seen, `make' will replace the percent in
 each pattern in the list with NAME and perform the above directory
 searches using that library filename.  If no library is found, the next
 word in the list will be used.
 
    The default value for `.LIBPATTERNS' is `lib%.so lib%.a', which
 provides the default behavior described above.
 
    You can turn off link library expansion completely by setting this
 variable to an empty value.
 

Info Catalog

(make.info.gz) Implicit/Search

(make.info.gz) Directory Search