请教一个sed命令(仅限于sed)

legone2008

一个a.xml内容格式如下：
<para lifetime="2" subjectname="Subj_A" tablename="TAB_A" timekey="TIMEVALUE"/>
<para lifetime="2" subjectname="Subj_B" tablename="TAB_B" timekey="TIMEVALUE"/>
<para lifetime="2" subjectname="Subj_C" tablename="TAB_C" timekey="TIMEVALUE"/>
<para lifetime="2" subjectname="Subj_D" tablename="TAB_D" timekey="TIMEVALUE"/>
<para lifetime="2" subjectname="Subj_E" tablename="TAB_E" timekey="TIMEVALUE"/>


想找出文本中目前已知某个subjectname和tablename的值，根据这两个条件修改以上xml记录，将这两个作用条件匹配的行中lifetime修改成指定的数值。

比如变量subjectname="Subj_B",tablename="TAB_B", 这两个值作为变量传sed中，通过sed来修改lifetime的值， xml中属性顺序不固定，有可能tablename在subjectname前面。

请教一下如何用sed命令来实现.

我尝试了一下，不知道有没有bug

sed -i '/'${subjectname}'/{/'${tablename}'/s/lifetime="[0-9]*"/lifetime=\"'${lifetime}'\"/g}'

seesea2517

p 的位置有问题，或者放最后面，或者不要p，连 -n 也不要。
当然，你不是要改文件吗？那需要 -i 选项了不是。

1. [seesea@UC ~]# ./xml.sh name table 4
   
2. <para lifetime="2" subjectname="Subj_A" tablename="TAB_A" timekey="TIMEVALUE"/>
   
3. <para lifetime="2" subjectname="Subj_B" tablename="TAB_B" timekey="TIMEVALUE"/>
   
4. <para lifetime="2" subjectname="subj" tablename="tab" timekey="TIMEVALUE"/>
   
5. <para lifetime="2" subjectname="Subj_D" tablename="TAB_D" timekey="TIMEVALUE"/>
   
6. <para lifetime="2" subjectname="Subj_E" tablename="TAB_E" timekey="TIMEVALUE"/>
   
7. <para lifetime="4" subjectname="name" tablename="table" timekey="TIMEVALUE"/>
   
8. [seesea@UC ~]# cat xml.sh
   
9. #! /bin/sh -
   
10. 
    
11. subjectname=$1
    
12. tablename=$2
    
13. lifetime=$3
    
14. sed "/subjectname=\"$subjectname\"/{/tablename=\"$tablename\"/s/lifetime=\"[0-9]\+\"/lifetime=\"$lifetime\"/}" xml.txt
    
15. # sed -n "/${subjectname}/{/${tablename}/s/lifetime=\"[0-9]*\"/lifetime=\"${lifetime}\"/p}" xml.txt

复制代码

yestreenstars

没发现漏洞~

elu_ligao

1. [redhat@localhost 1107]$ cat xml.txt
   
2. <para lifetime="2" subjectname="Subj_A" tablename="TAB_A" timekey="TIMEVALUE"/>
   
3. <para lifetime="2" subjectname="Subj_B" tablename="TAB_B" timekey="TIMEVALUE"/>
   
4. <para lifetime="2" subjectname="subj" tablename="tab" timekey="TIMEVALUE"/>
   
5. <para lifetime="2" subjectname="Subj_D" tablename="TAB_D" timekey="TIMEVALUE"/>
   
6. <para lifetime="2" subjectname="Subj_E" tablename="TAB_E" timekey="TIMEVALUE"/>
   
7. <para lifetime="2" subjectname="name" tablename="table" timekey="TIMEVALUE"/>
   
8. [redhat@localhost 1107]$ cat xml.sh
   
9. #! /bin/sh -
   
10. 
    
11. subjectname=$1
    
12. tablename=$2
    
13. lifetime=$3
    
14. #sed -n "/subjectname=\"$subjectname\"/{/tablename=\"$tablename\"/s/lifetime=\"[0-9]\+\"/lifetime=\"$lifetime\"/p}" xml.txt
    
15. sed -n "/${subjectname}/{/${tablename}/s/lifetime=\"[0-9]*\"/lifetime=\"${lifetime}\"/p}" xml.txt
    
16. [redhat@localhost 1107]$ sh xml.sh name table 4
    
17. <para lifetime="4" subjectname="Subj_A" tablename="TAB_A" timekey="TIMEVALUE"/>
    
18. <para lifetime="4" subjectname="Subj_B" tablename="TAB_B" timekey="TIMEVALUE"/>
    
19. <para lifetime="4" subjectname="subj" tablename="tab" timekey="TIMEVALUE"/>
    
20. <para lifetime="4" subjectname="Subj_D" tablename="TAB_D" timekey="TIMEVALUE"/>
    
21. <para lifetime="4" subjectname="Subj_E" tablename="TAB_E" timekey="TIMEVALUE"/>
    
22. <para lifetime="4" subjectname="name" tablename="table" timekey="TIMEVALUE"/>
    
23. [redhat@localhost 1107]$ cat xml.sh
    
24. #! /bin/sh -
    
25. 
    
26. subjectname=$1
    
27. tablename=$2
    
28. lifetime=$3
    
29. 
    
30. sed -n "/subjectname=\"$subjectname\"/{/tablename=\"$tablename\"/s/lifetime=\"[0-9]\+\"/lifetime=\"$lifetime\"/p}" xml.txt
    
31. #sed -n "/${subjectname}/{/${tablename}/s/lifetime=\"[0-9]*\"/lifetime=\"${lifetime}\"/p}" xml.txt
    
32. [redhat@localhost 1107]$ sh xml.sh name table 4
    
33. <para lifetime="4" subjectname="name" tablename="table" timekey="TIMEVALUE"/>

复制代码

回复 1# legone2008