maximum command line parameter length? 命令行参数可以有多长？

作者：半瓶墨水链接：http://www.2maomao.com/blog/maximum-command-line-parameter-length/

同事问了一个相关的问题，以前猜测是1024，验证了一下，居然是8196

Python语言: maximum command line parameter length? 命令行参数可以有多长？

#how long can a command line parameter have?
#
# Directly answer is 8196 on Window7(not sure about other platform)
#
#It’s easy to write a script to repro it:
#1. In one script, output the parameter it got, say script#1
#2. In another script, recursively execute script#1 and increase parameter step by step,
#   capture the output, see if you have the same with the parameter you give
#
# Usage: python test2.py
#        then you got the result
#        (if it's 10000, then adjust "end" variable below)
#
#— test.py —
importsys
printsys.argv[1]
 #— test2.py —
 import sys,os
 param = 'a'
 start = 0
 end =  10000
 while start < end: #binary search to speed up
     mid = (start + end) / 2
     param = 'a' * mid
     cmdline = 'test.py ' + param
     out = os.popen(cmdline).read().rstrip()
     if param == out:
         start = mid + 1
     else:
         end = mid - 1
     print len(param)
 print "\nMax Command Line Length=", start
 #What I got on Window7 is: 8153
 #  considering cmd.exe starts with "C:\\Windows\\system32\\cmd.exe /c test.py "
 #  then the maximum is about 8196