I'm having trouble with reading information back into a program from a binary file. when i try to display the contents of the file i get a Memory fault(coredump). would anyone be able to assist?
this is my fread line fread(&file_data,sizeof(struct book_type),1,fileSave); ive also tried it without... (3 Replies)
Hi I was hoping that maybe someone could help me with a small piece of C code. I have a number of files, which are all of similar layout ie. three lines of text and 5-6 columns of numerical data. I need to add each of the elements of the second column in one file to their counterparts in the second... (17 Replies)
Hi,
How can I remove all non numerical data from line, so I don't want to delete the line but to have only the numbers.
e.g.:
#########
123
aaa124
125bbb
126
127
#########
So I want all the leading and trailing non numerical stuff(letters/white space/tabs anything else except... (10 Replies)
I need to distinguish between numerical characters in a script:
echo "Enter a number."
read num
if (( $num = * )) ; then
exit 0
fi
this RegX does not work.
Any suggestions? (5 Replies)
So, I will be working with someone and basically we are trying to build a form that is submitted most likely via the web and the data is just a string of numbers.
like:
19383882872201110929282821818182827349190102837364718191001932873711
Now, each number is part of a numerical value of... (4 Replies)
this is my code and no matter what record number the user enters i cant get any of the records fields to read into the structure acct. What am i doing wrong?
#include <stdio.h>
typedef struct
{
char name;
int number;
float balance;
} acct_info_t;
int main (int... (0 Replies)
Hi experts,
I have a list of files containing forces as the only number as follows.
Force1.txt Force2.txt Force3.txt Force4.txt Force5.txt . . . . . . . . . Force100.txt I want to put all the data(only a number ) in these forces files in the file with the same order like 1,2,3 ..100 .... (2 Replies)
Hello,
I have two files, f1 and f2. f1 has 5 columns like so:
a b c d 154
e f g h 365
.....
f2 has two columns, the first column contains the name of the above file and second column contains a constant which is to be used for division.
e.g.
file1 56
I want to divide the 5th... (2 Replies)
Dear Gurus
I am stuck with the peice of work and do not know from where to start.
I get a machine generated file which is binary file contain binary data, i want to read binary data as it is without converting into any other format.
i want to read byte by byte.
Please let me know what... (24 Replies)
Discussion started by: guddu_12
24 Replies
LEARN ABOUT OSX
io::atomicfile
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 v5.16.2 2005-02-10 IO::AtomicFile(3)