Python 中os.system() 与os.exec*() 的区别

在用高通的平台做Android开发时，Modem端的软件经常需要手动Push进去，并且文件有很多。用ADB命令手动Push进去很麻烦，所以写了一个脚本来干活。
Modem的文件都是以modem开头的
modem.b00, modem.b10, modem_fw.b11, xxx

#!/usr/bin/env python

########################################################
#
# Author:  Winva
# Date: 2012-7-9
########################################################

'''
This script is used for pushing modem firmware to Phone.
PC dirctory fm/modemXXX, phone /system/etc/firmware
run $adb push XXX /system/etc/firmware
Current can run on Linux, for Window need change '/' to '\\'
'''

import sys
import re
import os

# find files and do push

help = '''Usage: AutoPush inputDirectoryPC matchString outputDirectoryPhone
matchString: string to match the file name
inputDirectoryPC:  directory that includes the input files
outputDirectoryPhone: directory in phone that the files are pushed to
Example: AutoPush ~/fm/ modem /system/etc/firmware
'''

def main():
    # check parameters
    argn = len(sys.argv)
    if argn == 1 :
        print 'You must input the input directory!'
        print help
        sys.exit()
    elif argn == 2 :
        path = sys.argv[1]
        matchString = 'modem'
        phoneDirectory = '/system/etc/firmware'
    elif argn == 3 :
        path = sys.argv[1]
        matchString = sys.argv[2]
        phoneDirectory = '/system/etc/firmware'
    else :
        path = sys.argv[1]
        matchString = sys.argv[2]
        phoneDirectory = sys.argv[3]

    if os.path.isdir(path) :
        print path
    else :
        print 'Error, %s not exist!' % path
        sys.exit()       


    # if path has a '/' for linux or '\\' for win?
    # in case of missing a '/'
    if path[-1] != '/' :
        path = path + '/'

    fileList = os.listdir(path)     
    foundFileNumber = 0
    for fileName in fileList :
        file = path + fileName
        print file
        # if the file is match?
        m = re.match(matchString, fileName)
        if m is not None :
            if os.path.isfile(file) :
                # Execute the operation 
                print 'Found a file: %s' % fileName
                os.execlp('adb','adb', 'push',file, phoneDirectory )
                foundFileNumber += 1

    print '%d files handled!' % foundFileNumber

if __name__ == '__main__':
  main()
  
运行程序：$ ./AutoPy.py firmware/
但是只有一个文件被Push进去了，看来是execlp()把Process抢走了，执行完了就退出了。
仔细查了一下Python的帮助
os.exec*()
The various exec*() functions take a list of arguments for the new program loaded into the process.   
These functions all execute a new program, replacing the current process; they do not return. On Unix, the new executable is loaded into the current process, and will have the same process id as the caller. Errors will be reported as OSError exceptions.
The current process is replaced immediately.
当前的shell会被Adb程序替代，所以执行一次就退出。

还有另外一个函数
os.system(command) 
Execute the command (a string) in a subshell. This is implemented by calling the Standard C function system(), and has the same limitations. 
这个命令是在subshell里执行，执行完还会回到shell。

改成这样就可以了：
                cmd = 'adb push ' + file + ' ' +  phoneDirectory
                os.system(cmd)