If you read from a file and write to the same file in one operation, you'll end up corrupting the file. Work-around is to write to a temp file and then rename the temp file.
This User Gave Thanks to balajesuri For This Post:
Hi i have wriiten a script which fetches the data from text file, and saves in the output in a text file itself, but i want that the output should save in different columns.
I have the output like:
For Channel:response_time__24.txt
1547 data points
0.339
0.299
0.448
0.581
7.380
... (1 Reply)
Hi
I need to execute a select statement in a solaris environment with oracle database. The select statement returns number of rows of data.
I need the data to be inserted into a CSV file with proper format. For that we normally use "You have to select all your columns as one big string,... (2 Replies)
Hi Unix gurus,
Maybe it is too much to ask for but please take a moment and help me out. A very humble request to you gurus. I'm new to Unix and I have started learning Unix. I have this project which is way to advanced for me.
File format: CSV file
File has four columns with no header... (8 Replies)
Hi,
I have a text file with the following format. Some of the fields are blank.
1234 3456 23 45464 327837283232 343434
5654353 34 34343 3434345 434242
....
....
....
I need to convert this file to a CSV file, like
1234, ,23, ... (3 Replies)
FILE_ID extraction from file name and save it in CSV file after looping through each folders
My files are located in UNIX Server, i want to extract file_id and file_name from each file .and save it in a CSV file. How do I do that?
I have folders in unix environment, directory structure is... (15 Replies)
Hi Friends,
I'm a great fan of this forum... it has helped me tone my skills in shell scripting. I have a challenge here, which I'm sure you guys would help me in achieving...
File A has a list of job ids and I need to compare this with the File B (*.log) and File C (extend *.log) and copy... (6 Replies)
Hi,
I have a file of csv data, which looks like this:
file1:
1AA,LGV_PONCEY_LES_ATHEE,1,\N,1,00020460E1,0,\N,\N,\N,\N,2,00.22335321,0.00466628
2BB,LES_POUGES_ASF,\N,200,200,00006298G1,0,\N,\N,\N,\N,1,00.30887539,0.00050312... (10 Replies)
Hi, I am newbie in shell script.
I need your help to solve my problem.
Firstly, I have 2 files of csv and i want to compare of the contents then the output will be written in a new csv file.
File1:
SourceFile,DateTimeOriginal
/home/intannf/foto/IMG_0713.JPG,2015:02:17 11:14:07... (8 Replies)
Hi,
I have another problem. I want to sort another csv file by the first field.
result.csv
SourceFile,Airspeed,GPSLatitude,GPSLongitude,Temperature,Pressure,Altitude,Roll,Pitch,Yaw
/home/intannf/foto5/2015_0313_090651_219.JPG,0.,-7.77223,110.37310,30.75,996.46,148.75,180.94,182.00,63.92 ... (2 Replies)
Discussion started by: refrain
2 Replies
LEARN ABOUT MOJAVE
io::atomicfile5.18
IO::AtomicFile(3) User Contributed Perl Documentation IO::AtomicFile(3)NAME
IO::AtomicFile - write a file which is updated atomically
SYNOPSIS
use IO::AtomicFile;
### Write a temp file, and have it install itself when closed:
my $FH = IO::AtomicFile->open("bar.dat", "w");
print $FH "Hello!
";
$FH->close || die "couldn't install atomic file: $!";
### Write a temp file, but delete it before it gets installed:
my $FH = IO::AtomicFile->open("bar.dat", "w");
print $FH "Hello!
";
$FH->delete;
### Write a temp file, but neither install it nor delete it:
my $FH = IO::AtomicFile->open("bar.dat", "w");
print $FH "Hello!
";
$FH->detach;
DESCRIPTION
This module is intended for people who need to update files reliably in the face of unexpected program termination.
For example, you generally don't want to be halfway in the middle of writing /etc/passwd and have your program terminate! Even the act of
writing a single scalar to a filehandle is not atomic.
But this module gives you true atomic updates, via rename(). When you open a file /foo/bar.dat via this module, you are actually opening a
temporary file /foo/bar.dat..TMP, and writing your output there. The act of closing this file (either explicitly via close(), or
implicitly via the destruction of the object) will cause rename() to be called... therefore, from the point of view of the outside world,
the file's contents are updated in a single time quantum.
To ensure that problems do not go undetected, the "close" method done by the destructor will raise a fatal exception if the rename() fails.
The explicit close() just returns undef.
You can also decide at any point to trash the file you've been building.
AUTHOR
Primary Maintainer
David F. Skoll (dfs@roaringpenguin.com).
Original Author
Eryq (eryq@zeegee.com). President, ZeeGee Software Inc (http://www.zeegee.com).
REVISION
$Revision: 1.2 $
perl v5.18.2 2005-02-10 IO::AtomicFile(3)