i have been googling, and came to the conclusion that there is not standard C library (or commonly used) that reads a complete line of a file, without a size parameter being involved.
so, as a little exercise i decided to think it over, and make my own
i came up with an idea, and wanted to hear comments (keeping in mind i want to learn from this)
the idea, in pseudo bable would be like this
Code:
char * readholeline ( FILE *file, size_t chunk);
{
while we dont hit the end of line
{
allocate a size of chunk array
read chunk bytes into array
add array into a new node of a linked list
}
calculate how many chars we have counting all nodes
allocate memory for all chars
while we still have have more nodes
{
copy string from node to "all chars string"
next node
free previous node
}
return "all chars pointer"
}
i discarded readin one char at a time, because it would be i/o intensive, and added the chunk parameter, because most of the time we have "some idea" of how big a file is, so we can make a "close" guess, but not quite exact ...
im still writing the real code, but wanted to know what other would think, or if someone has a better approach too
All Expert,
I am using Sun OS 5.8 and Perl version 5 in One server and Perl 5.8 in another unix server.
I am able to read a file using fopen function of perl --file size having more then 3 GB of data.(In the machine where Perl 5.8 install)
But when i am running the same perl script --It... (1 Reply)
Hi,
I am a beginner in shell scripting. I have written the following script, which is supposed to process the while loop for each line in the sid_home.txt file. But I'm getting the 'end of file' unexpected for the last line. The file sid_home.txt gets generated as expected, but the script... (6 Replies)
So, I want to read line-by-line a text file with unknown number of files....
So:
a=1
b=1
while ; do
b=`sed -n '$ap' test`
a=`expr $a + 1`
$here do something with b etc
done
the problem is that sed does not seem to recognise the $a, even when trying
sed -n ' $a p'
So, I cannot read... (3 Replies)
I need some help. I would like to read in a text file.
Take a variable such as ROW-D-01, compare it to what's in one line in the text file such as PROD/VM/ROW-D-01 and only input PROD/VM into a variable without the /ROW-D-01.
Is this possible? any help is appreciated. (2 Replies)
Hi,
I want to read a live log file line by line and considering those line which start from time stamp;
Below code I am using, which read line but throws an exception when comparing line that does not contain error code
tail -F /logs/COMMON-ERROR.log | while read myline; do... (2 Replies)
I need to copy a file (srcFile) to a new ubication (destFile). Then I calculate the size of the copy file using stat. The problem is that I always get a cero size value although the file has not cero size in the hard disk.
The source code that does this is :
PROGRAM 1:
char srcFile;... (4 Replies)
Hi All,
i want to write a shell script read below file line by line and want to exclude the lines which contains empty value for MOUNTPOINT field.
i am using centos 7 Operating system.
want to read below file.
# cat /tmp/d5
NAME="/dev/sda" TYPE="disk" SIZE="60G" OWNER="root"... (4 Replies)
Discussion started by: balu1234
4 Replies
LEARN ABOUT V7
pack_fopen_chunk
pack_fopen_chunk(3alleg4) Allegro manual pack_fopen_chunk(3alleg4)NAME
pack_fopen_chunk - Opens a sub-chunk of a file. Allegro game programming library.
SYNOPSIS
#include <allegro.h>
PACKFILE *pack_fopen_chunk(PACKFILE *f, int pack);
DESCRIPTION
Opens a sub-chunk of a file. Chunks are primarily intended for use by the datafile code, but they may also be useful for your own file rou-
tines. A chunk provides a logical view of part of a file, which can be compressed as an individual entity and will automatically insert and
check length counts to prevent reading past the end of the chunk. The PACKFILE parameter is a previously opened file, and `pack' is a bool-
ean parameter which will turn compression on for the sub-chunk if it is non-zero. Example:
PACKFILE *output = pack_fopen("out.raw", "w!");
...
/* Create a sub-chunk with compression. */
output = pack_fopen_chunk(output, 1);
if (!output)
abort_on_error("Error saving data!");
/* Write some data to the sub-chunk. */
...
/* Close the sub-chunk, recovering parent file. */
output = pack_fclose_chunk(output);
The data written to the chunk will be prefixed with two length counts (32-bit, a.k.a. big-endian). For uncompressed chunks these will both
be set to the size of the data in the chunk. For compressed chunks (created by setting the `pack' flag), the first length will be the raw
size of the chunk, and the second will be the negative size of the uncompressed data.
To read the chunk, use the following code:
PACKFILE *input = pack_fopen("out.raw", "rp");
...
input = pack_fopen_chunk(input, 1);
/* Read data from the sub-chunk and close it. */
...
input = pack_fclose_chunk(input);
This sequence will read the length counts created when the chunk was written, and automatically decompress the contents of the chunk if it
was compressed. The length will also be used to prevent reading past the end of the chunk (Allegro will return EOF if you attempt this),
and to automatically skip past any unread chunk data when you call pack_fclose_chunk().
Chunks can be nested inside each other by making repeated calls to pack_fopen_chunk(). When writing a file, the compression status is
inherited from the parent file, so you only need to set the pack flag if the parent is not compressed but you want to pack the chunk data.
If the parent file is already open in packed mode, setting the pack flag will result in data being compressed twice: once as it is written
to the chunk, and again as the chunk passes it on to the parent file.
RETURN VALUE
Returns a pointer to the sub-chunked PACKFILE, or NULL if there was some error (eg. you are using a custom PACKFILE vtable).
SEE ALSO pack_fclose_chunk(3alleg4), pack_fopen(3alleg4)Allegro version 4.4.2 pack_fopen_chunk(3alleg4)
10-21-2009
