python 小程序，替换文件中的字符串

Posted 2020-08-08

 1 [[email protected] ~]# cat passwd 
 2 root:x:0:0:root:/root:/bin/bash
 3 bin:x:1:1:bin:/bin:/sbin/nologin
 4 daemon:x:2:2:daemon:/sbin:/sbin/nologin
 5 adm:x:3:4:adm:/var/adm:/sbin/nologin
 6 lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin
 7 sync:x:5:0:sync:/sbin:/bin/sync
 8 shutdown:x:6:0:shutdown:/sbin:/sbin/shutdown
 9 halt:x:7:0:halt:/sbin:/sbin/halt
10 [[email protected] ~]# 
11 [[email protected] ~]# python 5.py passwd 0 1
12 [[email protected] ~]# 
13 [[email protected] ~]# cat passwd 
14 root:x:1:1:root:/root:/bin/bash
15 bin:x:1:1:bin:/bin:/sbin/nologin
16 daemon:x:2:2:daemon:/sbin:/sbin/nologin
17 adm:x:3:4:adm:/var/adm:/sbin/nologin
18 lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin
19 sync:x:5:1:sync:/sbin:/bin/sync
20 shutdown:x:6:1:shutdown:/sbin:/sbin/shutdown
21 halt:x:7:1:halt:/sbin:/sbin/halt
22 [[email protected] ~]# 
23 [[email protected] ~]# python 5.py passwd 1 2 passwd.new
24 [[email protected] ~]# 
25 [[email protected] ~]# cat passwd
26 root:x:1:1:root:/root:/bin/bash
27 bin:x:1:1:bin:/bin:/sbin/nologin
28 daemon:x:2:2:daemon:/sbin:/sbin/nologin
29 adm:x:3:4:adm:/var/adm:/sbin/nologin
30 lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin
31 sync:x:5:1:sync:/sbin:/bin/sync
32 shutdown:x:6:1:shutdown:/sbin:/sbin/shutdown
33 halt:x:7:1:halt:/sbin:/sbin/halt
34 [[email protected] ~]# 
35 [[email protected] ~]# cat passwd.new 
36 root:x:2:2:root:/root:/bin/bash
37 bin:x:2:2:bin:/bin:/sbin/nologin
38 daemon:x:2:2:daemon:/sbin:/sbin/nologin
39 adm:x:3:4:adm:/var/adm:/sbin/nologin
40 lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin
41 sync:x:5:2:sync:/sbin:/bin/sync
42 shutdown:x:6:2:shutdown:/sbin:/sbin/shutdown
43 halt:x:7:2:halt:/sbin:/sbin/halt
44 [[email protected] ~]# 
45 [[email protected] ~]# python 5.py passwd o
46 参数错误：python 5.py 需要编辑的文件 被替换的字符串 提成成的字符串 [另存成的文件]
47 [[email protected] ~]# python 5.py passw 1 2
48 文件不存在
49 [[email protected] ~]# 

 

脚本代码如下：

 

 1 #!/usr/bin/python
 2 # -*- coding=UTF-8 -*-
 3 
 4 import sys
 5 import os
 6 
 7 len_argv=len(sys.argv)
 8 #print ‘传参数量‘,len_argv-1
 9 
10 if   len_argv <  4:
11     print ‘参数错误：python ‘+sys.argv[0]+‘ 需要编辑的文件 被替换的字符串 提成成的字符串 [另存成的文件]‘
12 
13 elif len_argv >  5:
14     print ‘参数错误：python ‘+sys.argv[0]+‘ 需要编辑的文件 被替换的字符串 提成成的字符串 [另存成的文件]‘
15 
16 else:
17     if not os.path.isfile(sys.argv[1]):
18         print ‘文件不存在‘
19         sys.exit()
20     s_file  = file(sys.argv[1],‘r+‘)
21     old_str = sys.argv[2]
22     new_str = sys.argv[3]
23     d_file  = file(sys.argv[1]+‘.tmp‘,‘w‘)
24     for line in s_file.readlines():
25         d_file.writelines(line.replace(old_str,new_str))
26     s_file.close()
27     d_file.close()
28 
29     if len_argv == 4:
30         os.rename(sys.argv[1]+‘.tmp‘,sys.argv[1])
31     else:
32         os.rename(sys.argv[1]+‘.tmp‘,sys.argv[4])