Linux and UNIX Man Pages

Linux & Unix Commands - Search Man Pages

pcap_create(3pcap) [debian man page]

PCAP_CREATE(3PCAP)														PCAP_CREATE(3PCAP)

NAME
pcap_create - create a live capture handle SYNOPSIS
#include <pcap/pcap.h> char errbuf[PCAP_ERRBUF_SIZE]; pcap_t *pcap_create(const char *source, char *errbuf); DESCRIPTION
pcap_create() is used to create a packet capture handle to look at packets on the network. source is a string that specifies the network device to open; on Linux systems with 2.2 or later kernels, a source argument of "any" or NULL can be used to capture packets from all interfaces. The returned handle must be activated with pcap_activate() before packets can be captured with it; options for the capture, such as promis- cuous mode, can be set on the handle before activating it. RETURN VALUE
pcap_create() returns a pcap_t * on success and NULL on failure. If NULL is returned, errbuf is filled in with an appropriate error mes- sage. errbuf is assumed to be able to hold at least PCAP_ERRBUF_SIZE chars. SEE ALSO
pcap(3PCAP), pcap_activate(3PCAP) 5 April 2008 PCAP_CREATE(3PCAP)

Check Out this Related Man Page

PCAP_OPEN_LIVE(3PCAP)													     PCAP_OPEN_LIVE(3PCAP)

NAME
pcap_open_live - open a device for capturing SYNOPSIS
#include <pcap/pcap.h> char errbuf[PCAP_ERRBUF_SIZE]; pcap_t *pcap_open_live(const char *device, int snaplen, int promisc, int to_ms, char *errbuf); DESCRIPTION
pcap_open_live() is used to obtain a packet capture handle to look at packets on the network. device is a string that specifies the net- work device to open; on Linux systems with 2.2 or later kernels, a device argument of "any" or NULL can be used to capture packets from all interfaces. snaplen specifies the snapshot length to be set on the handle. promisc specifies if the interface is to be put into promiscuous mode. to_ms specifies the read timeout in milliseconds. RETURN VALUE
pcap_open_live() returns a pcap_t * on success and NULL on failure. If NULL is returned, errbuf is filled in with an appropriate error message. errbuf may also be set to warning text when pcap_open_live() succeeds; to detect this case the caller should store a zero-length string in errbuf before calling pcap_open_live() and display the warning to the user if errbuf is no longer a zero-length string. errbuf is assumed to be able to hold at least PCAP_ERRBUF_SIZE chars. SEE ALSO
pcap(3PCAP), pcap_create(3PCAP), pcap_activate(3PCAP) 5 April 2008 PCAP_OPEN_LIVE(3PCAP)
Man Page

13 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

Adding the individual columns of a matrix.

I have a huge matrix file containing some 1.5 million rows and 6000 columns. The matrix looks something like this: 1 2 3 4 5 6 7 8 9 3 4 5 I want to add all the numbers in the columns of this matrix and display the result to my stdout. This means that the numbers in the first column are: ... (2 Replies)
Discussion started by: shoaibjameel123
2 Replies

2. Shell Programming and Scripting

awk or sed - Convert 2 lines to 1 line

Hi, Just trying to get to grips with sed and awk for some reporting for work and I need some assistance: I have a file that lists policy names on the first line and then on the second line whether the policy is active or not. Policy Name: Policy1 Active: yes Policy... (8 Replies)
Discussion started by: guinch
8 Replies

3. Shell Programming and Scripting

How can I do this in VI editor?

version info : vi availabe with RHEL 5.4 I have a text file with 10,000 lines. I want to copy lines from 5000th line to 7000th and redirect to a file. Any idea how I can do this? Note: The above scenario is just an example. In my actual requirement, the file has 14 million lines and I want... (9 Replies)
Discussion started by: kraljic
9 Replies

4. Fedora

Is UNIX an open source OS ?

Hi everyone, I know the following questions are noobish questions but I am asking them because I am confused about the basics of history behind UNIX and LINUX. Ok onto business, my questions are-: Was/Is UNIX ever an open source operating system ? If UNIX was... (21 Replies)
Discussion started by: sreyan32
21 Replies

5. What is on Your Mind?

Introduction

Hello, I couldn't find an actual introduction thread, so I decided to just put this here. I go by d0wngrade online. I have been programming in multiple languages for about 15+ years. I started with standard web design languages like HTML and CSS, but I then advanced from design to development... (2 Replies)
Discussion started by: d0wngrade
2 Replies

6. UNIX for Advanced & Expert Users

Detecting unused variables...

Hi guys... The first active code line in AudioScope.sh is set -u . This causes a complete exit if a variable is used/found but has not been allocated at the start of the program. However, apart from writing code to do the task, is there a switch to to check which variables have been... (17 Replies)
Discussion started by: wisecracker
17 Replies

7. Shell Programming and Scripting

One instance of comparing grep and awk

Hi. In thread https://www.unix.com/shell-programming-and-scripting/267833-grouping-counting.html rovf and I had a mini-discussion on grep and awk. Here is a demo script that compares the awk and grep approaches for this single problem: #!/usr/bin/env bash # @(#) s2 Demonstrate group... (1 Reply)
Discussion started by: drl
1 Replies

8. Shell Programming and Scripting

Find columns in a file based on header and print to new file

Hello, I have to fish out some specific columns from a file based on the header value. I have the list of columns I need in a different file. I thought I could read in the list of headers I need, # file with header names of required columns in required order headers_file=$2 # read contents... (11 Replies)
Discussion started by: LMHmedchem
11 Replies

9. OS X (Apple)

Installing Dash Shell on OS X Lion

For those interested in installing dash shell on OSX Lion to help test POSIX compliancy of shell scripts, it is quite easy. I did it like this: If you don't have gcc on your system: 0. Download and install the Command Line Tools for Xcode package from Sign In - Apple * 1. Download the dash... (2 Replies)
Discussion started by: Scrutinizer
2 Replies

10. UNIX for Beginners Questions & Answers

Weird 'find' results

Hello and thanks in advance for any help anyone can offer me I'm trying to learn the find command and thought I was understanding it... Apparently I was wrong. I was doing compound searches and I started getting weird results with the -size test. I was trying to do a search on a 1G file owned by... (14 Replies)
Discussion started by: bodisha
14 Replies

11. UNIX for Beginners Questions & Answers

How to copy a column of multiple files and paste into new excel file (next to column)?

I have data of an excel files as given below, file1 org1_1 1 1 2.5 100 org1_2 1 2 5.5 98 org1_3 1 3 7.2 88 file2 org2_1 1 1 2.5 100 org2_2 1 2 5.5 56 org2_3 1 3 7.2 70 I have multiple excel files as above shown. I have to copy column 1, column 4 and paste into a new excel file as... (26 Replies)
Discussion started by: dineshkumarsrk
26 Replies

12. What is on Your Mind?

New UNIX and Linux History Sections

Dear All, Taking a break from Vue.js coding for the site, SEO and YT videos; and hopefully addressing some well deserved criticism from some here that I have been too focused on the visual aspects of the forums versus the substance and the community.... While the "current generation... (9 Replies)
Discussion started by: Neo
9 Replies

13. Programming

My first PERL incarnation... Audio Oscillograph

Hi all... Well guys and gals, I jumped in at the deep end and found things that PERL cannot do by default. Many tricky terminal escape codes are not catered for so I had to create workarounds. One thing I searched for was this: Passing perl variable to shell command AND, @Neo this was... (15 Replies)
Discussion started by: wisecracker
15 Replies