How to reduce the size of a file?

abhinav4 · 10-31-2010, 12:37 AM

How to reduce the size of a file. Is truncate related to this?If so can someone explain please

TobiSGD · 10-31-2010, 12:40 AM

You can reduce the size of a file by compressing it. In Linux you can use tools like gzip, bzip2, lzma, zip, rar and many more for this purpose.
Have a look at least at man gzip and man bzip2.

vikas027 · 10-31-2010, 12:47 AM

Hi Abhinav,
Yes the Truncate is sometimes related to file size. It means you delete all the contents of the file thereby making the size of the file 0 bytes.

It is often done as

Code:

cat /dev/null > /your/file/name

abhinav4 · 10-31-2010, 12:54 AM

Quote:

Originally Posted by vikas027

Hi Abhinav,
Yes the Truncate is sometimes related to file size. It means you delete all the contents of the file thereby making the size of the file 0 bytes.

It is often done as

Code:

cat /dev/null > /your/file/name

Actually sometimes when I see the log files which were archived after few lines it shows the message output truncated.... and then again it continues to show the later part. So just guessing how to perform this.

raviteja_s · 10-31-2010, 09:02 AM

hi,

echo " " > /var/log/messages

arizonagroovejet · 10-31-2010, 11:13 AM

Quote:

Originally Posted by raviteja_s

hi,

echo " " > /var/log/messages

That replaces the contents of /var/log/messages with a single space character.

There are lots of ways of making a file zero length that involve a lot of unnecessary typing. You can just use

Code:

>/var/log/messages

Davethesnake · 10-31-2010, 11:23 AM

yes you can reduce the sie of a file also by discarding unneccessary code/comments--refer to linux manual

abhinav4 · 10-31-2010, 10:40 PM

How do we truncate a file?

chrism01 · 11-01-2010, 12:36 AM

What language are you using eg C, shell ... ?

abhinav4 · 11-01-2010, 09:36 PM

Quote:

Originally Posted by chrism01

What language are you using eg C, shell ... ?

shell

arizonagroovejet · 11-02-2010, 05:15 AM

Quote:

Originally Posted by abhinav4

shell

Then you've been given three methods already in this thread. If none of them do what you want, I think you need to explain in greater detail what you mean by 'truncate'. The assumption has been that you mean 'make zero length'.

Mark1986 · 11-02-2010, 05:19 AM

Quote:

Originally Posted by arizonagroovejet

Then you've been given three methods already in this thread. If none of them do what you want, I think you need to explain in greater detail what you mean by 'truncate'. The assumption has been that you mean 'make zero length'.

And if your problem is solved, please state your solution and mark the thread as SOLVED. Also please give the reputation to those who helped you.

rew · 11-02-2010, 05:48 AM

The Unix system call "truncate" will do exactly that, but you can specify a number of bytes. So you can have a file called MyFile with
line 1
line 2
line 3

which has 7 bytes per line. So if I run
truncate 14 MyFile
only the first two lines are left.

I wrote my own version of the "truncate" program before this became a standard Linux utility. Here is a thread that mentions a source for the standard program (which happens to have the same interface as the one I wrote) http://mandrivausers.org/index.php?/...a-file-solved/