# delete line from file if successful partial string found **URL:** \ **Category:** UNIX for Advanced & Expert Users\ **Created:** [May 6, 2009, 8:49am UTC](https://community.unix.com/t/delete-line-from-file-if-successful-partial-string-found/239433 "2009-05-06T08:49:35Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![cronjob78](https://community.unix.com/letter_avatar/cronjob78/32/5_5575768a8748004e209b776fc1b2916d.png) [@cronjob78](https://community.unix.com/u/cronjob78)\ **Post date:** [May 6, 2009, 8:49am UTC](https://community.unix.com/t/delete-line-from-file-if-successful-partial-string-found/239433/1 "2009-05-06T08:49:35Z")
Id like to delete a line from a file using (preferably a single line unix command) if it contains a certain string pattern. If line contains "abcdef" then delete that line. Help greatly appreciated. ---
**Author:** ![ghostdog74](https://community.unix.com/letter_avatar/ghostdog74/32/5_5575768a8748004e209b776fc1b2916d.png) [@ghostdog74](https://community.unix.com/u/ghostdog74)\ **Post date:** [May 6, 2009, 9:17am UTC](https://community.unix.com/t/delete-line-from-file-if-successful-partial-string-found/239433/2 "2009-05-06T09:17:40Z")
```nohighlight # grep -v "abcdef" file > newfile ``` ---
**Author:** ![apsprabhu](https://community.unix.com/letter_avatar/apsprabhu/32/5_5575768a8748004e209b776fc1b2916d.png) [@apsprabhu](https://community.unix.com/u/apsprabhu)\ **Post date:** [May 7, 2009, 7:57am UTC](https://community.unix.com/t/delete-line-from-file-if-successful-partial-string-found/239433/3 "2009-05-07T07:57:05Z")
sed -i "/abcdef/d" \. this will remove the abcdef from the existing file. (take backup of the existing file before removing , if required) ---
**Author:** ![cronjob78](https://community.unix.com/letter_avatar/cronjob78/32/5_5575768a8748004e209b776fc1b2916d.png) [@cronjob78](https://community.unix.com/u/cronjob78)\ **Post date:** [May 12, 2009, 9:58am UTC](https://community.unix.com/t/delete-line-from-file-if-successful-partial-string-found/239433/4 "2009-05-12T09:58:29Z")
> [@apsprabhu](#): > > sed -i "/abcdef/d" \. this will remove the abcdef from the existing file. (take backup of the existing file before removing , if required) I know that. I want to say if abcdef is in the line then delete the ENTIRE line. Anyone know how I can do that? I need to do a huge number of files so while Im grateful for the first reply I cant go with it. ---
**Author:** ![vgersh99](https://community.unix.com/user_avatar/community.unix.com/vgersh99/32/14851_2.png) [@vgersh99](https://community.unix.com/u/vgersh99)\ **Post date:** [May 12, 2009, 10:34am UTC](https://community.unix.com/t/delete-line-from-file-if-successful-partial-string-found/239433/5 "2009-05-12T10:34:43Z")
> [@cronjob78](#): > > I know that. I want to say if abcdef is in the line then delete the ENTIRE line. > Anyone know how I can do that? have you tried the proposed code? Did it work? If not, what errors are you getting? > [@cronjob78](#): > > I need to do a huge number of files so while Im grateful for the first reply I cant go with it. Why is that? ---
**Author:** ![cronjob78](https://community.unix.com/letter_avatar/cronjob78/32/5_5575768a8748004e209b776fc1b2916d.png) [@cronjob78](https://community.unix.com/u/cronjob78)\ **Post date:** [May 12, 2009, 11:07am UTC](https://community.unix.com/t/delete-line-from-file-if-successful-partial-string-found/239433/6 "2009-05-12T11:07:42Z")
> [@vgersh99](#): > > have you tried the proposed code? > Did it work? If not, what errors are you getting? > > Why is that? I dont want to use the first one because I will need to run a command on on thousands of files. The second command didnt work. It didnt like the 'd' at the end of the command. If you must know its because a trojan filled them with large lines of code. There are a few patterns it left so Im hoping to delete them all in one go. The lines are painstakingly long so i cant just implement a sed command ---
**Author:** ![vgersh99](https://community.unix.com/user_avatar/community.unix.com/vgersh99/32/14851_2.png) [@vgersh99](https://community.unix.com/u/vgersh99)\ **Post date:** [May 12, 2009, 11:12am UTC](https://community.unix.com/t/delete-line-from-file-if-successful-partial-string-found/239433/7 "2009-05-12T11:12:53Z")
> [@cronjob78](#): > > I dont want to use the first one because I will need to run a command on on thousands of files. so why don't you put the command in a loop - processing one file at a time? > [@cronjob78](#): > > The second command didnt work. It didnt like the 'd' at the end of the command. strange - worked fine here. I don't the GNU sed with '-i' implemented, but the standard 'sed' did the job. > [@cronjob78](#): > > If you must know its because a trojan filled them with large lines of code. There are a few patterns it left so Im hoping to delete them all in one go. > The lines are painstakingly long so i cant just implement a sed command Why cannot you implement 'sed'? Have you tried it? ---
**Author:** ![apsprabhu](https://community.unix.com/letter_avatar/apsprabhu/32/5_5575768a8748004e209b776fc1b2916d.png) [@apsprabhu](https://community.unix.com/u/apsprabhu)\ **Post date:** [May 14, 2009, 2:35am UTC](https://community.unix.com/t/delete-line-from-file-if-successful-partial-string-found/239433/8 "2009-05-14T02:35:45Z")
> [@cronjob78](#): > > I know that. I want to say if abcdef is in the line then delete the ENTIRE line. > Anyone know how I can do that? > > I need to do a huge number of files so while Im grateful for the first reply I cant go with it. Hi Cronjob78, Have to tried this command " sed -i "/abcdef/d" \. " ???. This command not only removes the string adcdef, this will remove the entire line. I beleive i have posted this command only after testing. ------------------------------------------ See the below example...... -sh-3.1$ grep ABC aps\* aps1.txt:ABC aps1.txt:ABC123 aps1.txt:123ABC aps1.txt:ABCDEFGH aps1.txt:ABCDE123 aps1.txt:123456789ABC aps2.txt:ABCDEFGHIJKLMNOP aps2.txt:PRABHUABC aps2.txt:SHANKAR ABC aps2.txt:--ABC--- -sh-3.1$ sed -i "/ABC/d" aps\*txt -sh-3.1$ grep ABC aps\*