请大家帮忙解析一下这个makefile 文件

lijiehunan

makefile 文件是这样的：

CC=g++
CFLAGS=-c -Wall
LDFLAGS=
SOURCES=main.cpp hello.cpp factorial.cpp
OBJECTS=$(SOURCES:.cpp=.o)
EXECUTABLE=hello

all: $(SOURCES) $(EXECUTABLE)
       
$(EXECUTABLE): $(OBJECTS)
        $(CC) $(LDFLAGS) $(OBJECTS) -o $@

.cpp.o:
        $(CC) $(CFLAGS) $< -o $@

菜鸟一个，有几个地方看不懂：
1、OBJECTS=$(SOURCES:.cpp=.o)  ：SOURCES:.cpp=.o不知道是什么意思。

2、$< -o $@ 是不知道是什么意思，请指点一下。

liying_gg

1.OBJECTS= SOURCES 中的内容吧。cpp替换成。o

2.$< The name of the first prerequisite. If the target got its commands from an
implicit rule, this will be the first prerequisite added by the implicit rule

$@ The file name of the target of the rule. If the target is an archive member, then
‘$@’ is the name of the archive file. In a pattern rule that has multiple targets
‘$@’ is the name
of whichever target caused the rule’s commands to be run.