This example also is a good example of why I dislike '<<'; the pipe head is in the middle of the data structure:
This is with HP-UX old bits, your head and tail may differ, see the man pages!
Hi,
I have a simple question... In C do we have a standard library function which will return the pointer to a substring at certain offset and having certain length...
Ofcourse we should take care not to access beyond allocated length in the parent string and don't overwrite beyond allocated... (2 Replies)
Hi,
I want to read a file from a specified offset from the start of file. With the read command, is it possible to do so. Please suggest. Is there any other alternative?
Thanks,
Saurabh (2 Replies)
Hi all,
Does anybody know or guide me on how to remove the first N bytes and the last N bytes from a binary file? Is there any AWK or SED or any command that I can use to achieve this?
Your help is greatly appreciated!!
Best Regards,
Naveen. (1 Reply)
Hi, all.
I need to convert a file tab delimited/variable length file in AIX to a fixed lenght file delimited by spaces. This is the input file:
10200002<tab>US$ COM<tab>16/12/2008<tab>2,3775<tab>2,3783
19300978<tab>EURO<tab>16/12/2008<tab>3,28523<tab>3,28657
And this is the expected... (2 Replies)
Hi,
If I want to copy a 1024 byte data stream in to the target location in 3-bytes chunk, I guess I can use the following script.
dd bs=1024 count=3 if=/src of=/dest
But, I would like to know, how to do it via a C program. I have tried this with memcpy(), that did not help. (3 Replies)
Hello Everyone,
I am stuck with one issue while working on abstract flat file which i have to use as input and load data to table.
Input Data-
------ ------------------------ ---- -----------------
WFI001 Xxxxxx Control Work Item A Number of Records
------ ------------------------... (5 Replies)
Hello guys. I really hope someone will help me with this one..
So, I have to write this script who:
- creates a file home/student/vmdisk of 10 mb
- formats that file to ext3
- mounts that partition to /mnt/partition
- creates a file /mnt/partition/data. In this file, there will... (1 Reply)
hello,
suppose, entered input is of 1-40 bytes, i need it to be converted to 40 bytes exactly.
example: if i have entered my name anywhere between 1-40 i want it to be stored with 40 bytes exactly.
enter your name:
donald duck (this is of 11 bytes)
expected is as below - display 11... (3 Replies)
Hi,
I am trying to get the position of a repeated string in a line using
grep -b -o "pattern"
In my server I am using GNU grep version 2.14 and the code is working fine. However when I am deploying the same code in a different server which is using GNU grep version 2.5.1 the code is not... (3 Replies)
Dear all,
I want to offset the file numbers. can you please make some awk code or linux code for the same.
Example:
input file names
ANI_WFMASS_PIST00001.gif
ANI_WFMASS_PIST00002.gif
.
.
.
ANI_WFMASS_PIST0000n.gif
offset --> 30
ANI_WFMASS_PIST00031.gif
ANI_WFMASS_PIST00032.gif... (14 Replies)
Discussion started by: kri321shna
14 Replies
LEARN ABOUT LINUX
pcap-savefile
PCAP-SAVEFILE(5) File Formats Manual PCAP-SAVEFILE(5)NAME
pcap-savefile - libpcap savefile format
DESCRIPTION
NOTE: applications and libraries should, if possible, use libpcap to read savefiles, rather than having their own code to read savefiles.
If, in the future, a new file format is supported by libpcap, applications and libraries using libpcap to read savefiles will be able to
read the new format of savefiles, but applications and libraries using their own code to read savefiles will have to be changed to support
the new file format.
``Savefiles'' read and written by libpcap and applications using libpcap start with a per-file header. The format of the per-file header
is:
+------------------------------+
| Magic number |
+--------------+---------------+
|Major version | Minor version |
+--------------+---------------+
| Time zone offset |
+------------------------------+
| Time stamp accuracy |
+------------------------------+
| Snapshot length |
+------------------------------+
| Link-layer header type |
+------------------------------+
All fields in the per-file header are in the byte order of the host writing the file. The first field in the per-file header is a 4-byte
magic number, with the value 0xa1b2c3d4. The magic number, when read by a host with the same byte order as the host that wrote the file,
will have the value 0xa1b2c3d4, and, when read by a host with the opposite byte order as the host that wrote the file, will have the value
0xd4c3b2a1. That allows software reading the file to determine whether the byte order of the host that wrote the file is the same as the
byte order of the host on which the file is being read, and thus whether the values in the per-file and per-packet headers need to be byte-
swapped.
Following this are:
A 2-byte file format major version number; the current version number is 2.
A 2-byte file format minor version number; the current version number is 4.
A 4-byte time zone offset; this is always 0.
A 4-byte number giving the accuracy of time stamps in the file; this is always 0.
A 4-byte number giving the "snapshot length" of the capture; packets longer than the snapshot length are truncated to the snapshot
length, so that, if the snapshot length is N, only the first N bytes of a packet longer than N bytes will be saved in the capture.
a 4-byte number giving the link-layer header type for packets in the capture; see pcap-linktype(7) for the LINKTYPE_ values that can
appear in this field.
Following the per-file header are zero or more packets; each packet begins with a per-packet header, which is immediately followed by the
raw packet data. The format of the per-packet header is:
+---------------------------------------+
| Time stamp, seconds value |
+---------------------------------------+
| Time stamp, microseconds value |
+---------------------------------------+
| Length of captured packet data |
+---------------------------------------+
|Un-truncated length of the packet data |
+---------------------------------------+
All fields in the per-packet header are in the byte order of the host writing the file. The per-packet header begins with a time stamp
giving the approximate time the packet was captured; the time stamp consists of a 4-byte value, giving the time in seconds since January 1,
1970, 00:00:00 UTC, followed by a 4-byte value, giving the time in microseconds since that second. Following that are a 4-byte value giv-
ing the number of bytes of captured data that follow the per-packet header and a 4-byte value giving the number of bytes that would have
been present had the packet not been truncated by the snapshot length. The two lengths will be equal if the number of bytes of packet data
are less than or equal to the snapshot length.
SEE ALSO pcap(3PCAP), pcap-linktype(7)
21 October 2008 PCAP-SAVEFILE(5)