04-12-2011
9 More Discussions You Might Find Interesting
1. Shell Programming and Scripting
Hello,
I need to truncate a large file without deleting and touching it again.
i tried the below commands but no use because of the huge file size
cat <<! > errors
and
echo > errors
Could someone please help.
Thanks,
Sateesh (1 Reply)
Discussion started by: kotasateesh
1 Replies
2. Shell Programming and Scripting
I have one file which first line is blank and second line has some data.
$cat filename
output:
30-MAY-07
I want to store 30-MAY-07 value in one variable.
for that I wrote
var="`head -2 filename`"
It will give that result but I want to truncate the first line which is blank.
plz help. (2 Replies)
Discussion started by: rinku
2 Replies
3. Shell Programming and Scripting
Hi All,
I have an application which writes log in to a file. The file size becomes around min of 800 MB a day. So I have written a script which backup the file and truncate the original file. My script is like this
cp X.log /backup/X.log1
> X.log
But the second truncate command... (3 Replies)
Discussion started by: mvenkat_in
3 Replies
4. UNIX for Dummies Questions & Answers
I am trying to concatenate 2 files, but before concatenation, I would like to strip off the final character from the first file.
The final character is a form feed (ascii 012 / hex 0C) and there will be an unknown number of these characters in the file. It is only the very last one which I want... (1 Reply)
Discussion started by: Gwailo88
1 Replies
5. Shell Programming and Scripting
Hi,
I have files with names like file1.txt.txt.txt.txt and file2.txt.txt.txt.txt.txt............ (random infinite number of .txt exist).
how to truncate (mv) their names to ones with single .txt extension like file1.txt and file1.txt ? In other words, how to extract the filename upto first... (12 Replies)
Discussion started by: prvnrk
12 Replies
6. Shell Programming and Scripting
Hi all,
i have a file and i want that after 6th slash "/" in each line of the file the contents gets truncated.
Can anyone tell me how to do that !!
thanks in advance
One more thing how can i change the size of output buffer of console,
as i had very long output and its not... (2 Replies)
Discussion started by: glamo_2312
2 Replies
7. UNIX for Dummies Questions & Answers
Folder of e-mails in maildir format had been corrupted. Typical file name is 1246281161.6777.m21JH:2,S . The " :2,S prevents " copying to another device. How can I simply remove the last four characters? (2 Replies)
Discussion started by: steve900
2 Replies
8. Shell Programming and Scripting
Hello all.
I would like to make a script (or two shell scripts) that will do the following.
I need the maximum file name and directory name to be 38 characters long.
As well, if shortening the file name ends up making all of the files in that directory have the same name, then I would like... (9 Replies)
Discussion started by: marcozd
9 Replies
9. Shell Programming and Scripting
how to recover the file in unix.
Thanks in advance.:wall: (1 Reply)
Discussion started by: krbala1985
1 Replies
LEARN ABOUT NETBSD
ftruncate
TRUNCATE(2) BSD System Calls Manual TRUNCATE(2)
NAME
truncate, ftruncate -- truncate a file to a specified length
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#include <unistd.h>
int
truncate(const char *path, off_t length);
int
ftruncate(int fd, off_t length);
DESCRIPTION
truncate() causes the file named by path or referenced by fd to have a size of length bytes. If the file previously was larger than this
size, the extra data is discarded. If it was previously shorter than length, its size is increased to the specified value and the extended
area appears as if it were zero-filled.
With ftruncate(), the file must be open for writing; for truncate(), the process must have write permissions for the file.
RETURN VALUES
A value of 0 is returned if the call succeeds. If the call fails a -1 is returned, and the global variable errno specifies the error.
ERRORS
Error return codes common to truncate() and ftruncate() are:
[EISDIR] The named file is a directory.
[EROFS] The named file resides on a read-only file system.
[ETXTBSY] The file is a pure procedure (shared text) file that is being executed.
[EIO] An I/O error occurred updating the inode.
[ENOSPC] There was no space in the filesystem to complete the operation.
Error codes specific to truncate() are:
[ENOTDIR] A component of the path prefix is not a directory.
[ENAMETOOLONG] A component of a pathname exceeded {NAME_MAX} characters, or an entire path name exceeded {PATH_MAX} characters.
[ENOENT] The named file does not exist.
[EACCES] Search permission is denied for a component of the path prefix, or the named file is not writable by the user.
[ELOOP] Too many symbolic links were encountered in translating the pathname.
[EFAULT] path points outside the process's allocated address space.
Error codes specific to ftruncate() are:
[EBADF] The fd is not a valid descriptor.
[EINVAL] The fd references a socket, not a file, or the fd is not open for writing.
SEE ALSO
open(2)
STANDARDS
Use of truncate() to extend a file is an IEEE Std 1003.1-2004 (``POSIX.1'') extension, and is thus not portable. Files can be extended in a
portable way seeking (using lseek(2)) to the required size and writing a single character with write(2).
HISTORY
The truncate() and ftruncate() function calls appeared in 4.2BSD.
BUGS
These calls should be generalized to allow ranges of bytes in a file to be discarded.
BSD
March 16, 2008 BSD