Login or Register to Ask a Question and Join Our Community


UNIX for Dummies Questions & Answers

efficient way to find diff

 
Thread Tools Search this Thread
Top Forums UNIX for Dummies Questions & Answers efficient way to find diff
# 1  
Old 07-08-2011
efficient way to find diff
I have two files A and B. I want to create file C which is A - B. I am currently using

Code:
grep -v -f B A > C

Is there a more efficient way. Files A and B are both large files

Thanks
Last edited by radoulov; 07-08-2011 at 01:12 PM.. Reason: Code tags.
# 2  
Old 07-08-2011
Yes,
if file B contains fixed strings (as opposed to regular expressions), you should add the -F option (or use fgrep, if the mentioned option is not available).
# 3  
Old 07-08-2011
File B does contain regular exprs
# 4  
Old 07-08-2011
I would use the same command.
Eventually you may get errors (not enough memory) if the files get bigger.
 
Login or Register to Ask a Question

Previous Thread | Next Thread

10 More Discussions You Might Find Interesting

1. UNIX for Beginners Questions & Answers

Find number of ACTIVE SSH putty sessions, excluding where the user hopped on to a diff server

Hi - If iam logged on to server A, on 4 putty windows using SSH ... and out of these 4 logged-in sessions, in one of the sessions if i did SSH from server A to server B; i would now have 4 putty windows sessions ... of which 3 are actively logged on to Server A while 1 putty window is actively... (2 Replies)
Discussion started by: i4ismail
2 Replies

2. UNIX for Dummies Questions & Answers

Find diff between two patterns in two files and append

Hi, I'm a newbie at programming in Unix, and I seem to have a task that is greater than I can handle. Trying to learn awk by the way (but in the end, i just need something that works). My goal is to compare two files and output the difference between the two. I've been reading, and I think I... (5 Replies)
Discussion started by: legato22
5 Replies

3. Shell Programming and Scripting

serach diff filename in diff location using shell scripting

Hi, I am new to shell scripting. please help me to find out the solution. I need a script where we need to read the text file(consists of all file names) and get the file names one by one and append the date suffix for each file name as 'yyyymmdd' . Then search each file if exists... (1 Reply)
Discussion started by: Lucky123
1 Replies

4. Shell Programming and Scripting

.procmailrc and uudeview (put attachments from diff senders to diff folders)

Moderator, please, delete this topic (1 Reply)
Discussion started by: optik77
1 Replies

5. Shell Programming and Scripting

Find diff bet 2 files and store result in another file

Hi I want to compare 2 files. The files have the same amount of rows and columns. So each line must be compare against the other and if one differs from the other, the result of both must be stored in a seperate file. I am doing this in awk. Here is my file1: Blocks... (2 Replies)
Discussion started by: ladyAnne
2 Replies

6. Shell Programming and Scripting

to find the diff in a date

Hello, i have a variable where the present date is going to save. and i have another variable where the another date which will of higher value is going to save. I need to find the difference with respect to date,month and year. What the need is to send an e-mail if the difference in... (2 Replies)
Discussion started by: nagendramv
2 Replies

7. Shell Programming and Scripting

Simulate SVN diff using plain diff

Hi, svn diff does not work very well with 2 local folders, so I am trying to do this diff using diff locally. since there's a bunch of meta files in an svn directory, I want to do a diff that excludes everything EXCEPT *.java files. there seems to be only an --exclude option, so I'm not sure... (3 Replies)
Discussion started by: ackbarr
3 Replies

8. Shell Programming and Scripting

Find match in two diff file - local srv and remote server

Perl Guru.... I need to compare two diff file (file1.abc will locate in current server and file2.abc will locate in remote server), basically the script will look for match in both file and only will send out email if there is no match and also give me list of unmatch and dups as well. So... (0 Replies)
Discussion started by: amir07
0 Replies

9. UNIX for Advanced & Expert Users

Script to Find Diff from two folders

Hi I would like to find the diff between two folders: Ex: Folder:1 html.java go.java ten.java Folder:2html.java go.java ten.java you.java Questions comes: Folder:1 contains a files with old version, know the files were modified and updated with the new version in Folder2. I... (2 Replies)
Discussion started by: gkrishnag
2 Replies

10. Shell Programming and Scripting

diff 2 files; output diff's to 3rd file

Hello, I want to compare two files. All records in file 2 that are not in file 1 should be output to file 3. For example: file 1 123 1234 123456 file 2 123 2345 23456 file 3 should have 2345 23456 I have looked at diff, bdiff, cmp, comm, diff3 without any luck! (2 Replies)
Discussion started by: blt123
2 Replies
Login or Register to Ask a Question