opencv错误ld: library not found fo

一直以来使用opencv都是用cmake编译，然而cmake需要先cmake再make才能生成可执行文件，平时写小demo的时候感觉特麻烦，所有想写个Makefile直接make，Makefile文件长这样：

CC = g++
SRCS = helloword.cpp
PROG = helloword

OPENCV = `pkg-config opencv --cflags --libs`
LIBS = $(OPENCV)

$(PROG):$(SRCS)
    $(CC) -o $(PROG) $(SRCS) $(LIBS) -std=c++11

执行make命令的时候看到实际执行的命令是：

g++ `pkg-config --cflags opencv` `pkg-config --libs opencv` -o helloword helloword.cpp --std=c++11

然而出现了错误：

ld: library not found for -lippicv
clang: error: linker command failed with exit code 1 (use -v to see invocation)

使用cmake是可以正常编译运行的，说明opencv环境应该没问题，一再确认Makefile写法应该也没问题。报错意思貌似是ippicv这个library没找到，有可能是pkg-config的锅，google之，果然，，，问题在于ippicv这个库是个第三方的库，opencv的pkg-config文件opencv.pc只说要链接这个库，然而并没有给定这个库的链接，修改下这个文件就可以了，这个文件一般都是在opencv安装目录/lib/pkg-config/下，例如我的在

/usr/local/Cellar/opencv3/3.1.0_3/lib/pkgconfig/opencv.pc

修改这个文件为：

# Package Information for pkg-config

prefix=/usr/local/Cellar/opencv3/3.1.0_3
exec_prefix=${prefix}
libdir=${exec_prefix}/lib
libdir3rd=${exec_prefix}/share/OpenCV/3rdparty/lib
includedir_old=${prefix}/include/opencv
includedir_new=${prefix}/include


Name: OpenCV
Description: Open Source Computer Vision Library
Version: 3.1.0
Libs: -L${exec_prefix}/lib -L${libdir3rd} -lopencv_shape -lopencv_stitching -lopencv_objdetect -lopencv_superres -lopencv_videostab -lippicv -lopencv_calib3d -lopencv_features2d -lopencv_highgui -lopencv_videoio -lopencv_imgcodecs -lopencv_video -lopencv_photo -lopencv_ml -lopencv_imgproc -lopencv_flann -lopencv_core
Libs.private: -framework OpenCL -L/usr/local/Cellar/qt/4.8.7_2/lib -lQtGui -lQtTest -lQtCore -L/usr/local/opt/jpeg/lib -ljpeg -L/usr/local/lib -lwebp -lpng -ltiff -lImath -lIlmImf -lIex -lHalf -lIlmThread -L/usr/lib -lz -framework QTKit -framework QuartzCore -framework AppKit
Cflags: -I${includedir_old} -I${includedir_new}

搞定，收工！