main函数的参数 argc argv env

main中的参数 第一个表示程序命令行参数个数,第二个表示命令行字符指针数组,第三个表示环境变量的指针数组!

这是在特定的编译环境中才出现第三个参数!

下面是举例说明:


#include<stdio.h>


int main(int argc, char *argv[],char *env[])




...{


int i;


for(i = 0; i < argc; i++)


printf("%s%s%s", (i==0) ? "Arguments: " : "", argv[i], (i!=argc - 1) ? " " : " ");


while(*env!=NULL)


printf("%s ",*env++);


return 0;


}





保存为1.c

在cmd下执行: cl 1.c

执行1

结果:

Arguments: 1
ALLUSERSPROFILE=C:/Documents and Settings/All Users
APPDATA=C:/Documents and Settings/Administrator/Application Data
CLIENTNAME=Console
CommonProgramFiles=C:/Program Files/Common Files
COMPUTERNAME=A39
ComSpec=C:/WINDOWS/system32/cmd.exe
DDKROOT=c:/NTDDK
FP_NO_HOST_CHECK=NO
HOMEDRIVE=C:
HOMEPATH=/Documents and Settings/Administrator
include=C:/Program Files/Microsoft Visual Studio/VC98/atl/include;C:/Program Fil
es/Microsoft Visual Studio/VC98/mfc/include;C:/Program Files/Microsoft Visual St
udio/VC98/include
lib=C:/Program Files/Microsoft Visual Studio/VC98/mfc/lib;C:/Program Files/Micro
soft Visual Studio/VC98/lib
LOGONSERVER=//A39
MSDevDir=C:/Program Files/Microsoft Visual Studio/Common/MSDev98
NUMBER_OF_PROCESSORS=1
OS=Windows_NT
Path=C:/WINDOWS/system32;C:/WINDOWS;C:/WINDOWS/System32/Wbem;C:/Program Files/Mi
crosoft Visual Studio/Common/Tools/WinNT;C:/Program Files/Microsoft Visual Studi
o/Common/MSDev98/Bin;C:/Program Files/Microsoft Visual Studio/Common/Tools;C:/Pr
ogram Files/Microsoft Visual Studio/VC98/bin
PATHEXT=.COM;.EXE;.BAT;.CMD;.VBS;.VBE;.JS;.JSE;.WSF;.WSH
PROCESSOR_ARCHITECTURE=x86
PROCESSOR_IDENTIFIER=x86 Family 15 Model 1 Stepping 3, GenuineIntel
PROCESSOR_LEVEL=15
PROCESSOR_REVISION=0103
ProgramFiles=C:/Program Files
PROMPT=$P$G
Rav=C:/Documents and Settings/All Users/Application Data/Rising/Rav
SESSIONNAME=Console
SystemDrive=C:
SystemRoot=C:/WINDOWS
TEMP=C:/DOCUME~1/ADMINI~1/LOCALS~1/Temp
TMP=C:/DOCUME~1/ADMINI~1/LOCALS~1/Temp
USERDOMAIN=Admin
USERNAME=Administrator
USERPROFILE=C:/Documents and Settings/Administrator
windir=C:/WINDOWS