Search Order
When environment variables and command-line options are used together the compiler searches the directories in the following order:
- Command-line options '-I' and '-L',from left to right.
- Directories specified by environment variables,such as C_INCLUDE_PATH and LIBRARY_PATH.
- Default system directories.
Note:In day-to-day usage,directories are usually added to the search paths with the options '-I' and '-L'.
Creating a Library with ar
The GNU archiver ar combines a collection of objects files into a single archive file,also know as a library.An archive file is simply a convenient way of distributing a large number of related object files together.
- You can use the following command to create a static library:
$ ar cr libNAME.a file1.o file2.o ... filen.o
- The archiver ar also provides a "table of contents" option 't' to list the object files in an existing library.
$ ar t libNAME.a
EX：
main.c
mylib.h
func1.c
func2.c
使用
gcc -Wall * -c生成目標文件
目錄
使用
ar cr創(chuàng)建一個自己的庫文件：
libadd.a
第三種方法较店，使用默認庫：
使用庫文件編譯程序，生成可執(zhí)行文件：
add
注意文件的編譯順序：
第一種方法：
-L
第二種方法（通過環(huán)境變量）：
LIBRARY_PATH
注：添加：$LIBRARY_PATH是防止變量原有的的內容被沖掉，表示最佳環(huán)境變量
2020.11.18
