It works fine with or without numbers at the end. Change the value of "i" to the text your looking for. The major flaw is that it would only catch one instance even with the for loop. Also it could only use a single space delimeted string. Try this and change to your needs.
tmp.txt contains
this is a line of text
this is another line
that is yet another line
this is a line that's not the same
that line above is different!
this is the last line
Hi,
I have a file which contains many occurances of a string say "hellosunil".
I want to insert a newline charcater after all the "hellosunil" strings in the file.
trying to use sed,
sed -e 's/hellosunil/\\nhellosunil/g' file1
sed help says u cannot substitute a regular expression... (6 Replies)
Dear all,
I have a file created in the name sample.txt in UNIX with header and footer. How to insert a required string (for example "FILE1") in the header part after the file has been created. What kind of command can i use to do the same.
Thanks in advance
Hari (3 Replies)
i have a file contains like this:
i want to create a script that will insert a comma "." after the 10th character so it would be look like this
thanks in advance (5 Replies)
Hello
Can somebody please help me with the following script?
I'm trying to create a text file with 20 blank lines and then insert a string in line 2 but nothing is printed in the itxtfile. I can create the file with 20 blank lines but when I "tell" it to print something on the second line, it... (4 Replies)
Hello Mates,
I have one txt file having commo seperated values. I have to insert string "FALSE" in 2nd field from the end. E.G
SE18 6RN,,,,5439070,1786840,,1000002148671600,123434
Out put should be:
SE18 6RN,,,,5439070,1786840,FALSE,1000002148671600,123434
Can some one help me to... (8 Replies)
Hi,
I have a very long pipe delimited string. The length of the string could vary. For example:
START|one|two|three|four|five|six|seven
START|one|two|three|four|five|six|seven|eight|nine
START|one|two|three|four
I want to replace in the third occurence of string with another... (9 Replies)
Hi everyone,
I am trying to insert a single very long string as the first line of a file,
So the following sed commands does what I want;
sed '1i\"","a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z"' file.txt
Think that all the... (3 Replies)
I am getting some values from a file and putting them in an array..but the null strings are not getting passed to the array. So during printing the elements ,the null string is not showing in the output. during array size calculation it is also excluding null.Please let me know how to do it.
# cat... (2 Replies)
Discussion started by: millan
2 Replies
LEARN ABOUT PLAN9
pcap_loop
PCAP_LOOP(3PCAP)PCAP_LOOP(3PCAP)NAME
pcap_loop, pcap_dispatch - process packets from a live capture or savefile
SYNOPSIS
#include <pcap/pcap.h>
typedef void (*pcap_handler)(u_char *user, const struct pcap_pkthdr *h,
const u_char *bytes);
int pcap_loop(pcap_t *p, int cnt,
pcap_handler callback, u_char *user);
int pcap_dispatch(pcap_t *p, int cnt,
pcap_handler callback, u_char *user);
DESCRIPTION
pcap_loop() processes packets from a live capture or ``savefile'' until cnt packets are processed, the end of the ``savefile'' is reached
when reading from a ``savefile'', pcap_breakloop() is called, or an error occurs. It does not return when live read timeouts occur. A
value of -1 or 0 for cnt is equivalent to infinity, so that packets are processed until another ending condition occurs.
pcap_dispatch() processes packets from a live capture or ``savefile'' until cnt packets are processed, the end of the current bufferful of
packets is reached when doing a live capture, the end of the ``savefile'' is reached when reading from a ``savefile'', pcap_breakloop() is
called, or an error occurs. Thus, when doing a live capture, cnt is the maximum number of packets to process before returning, but is not
a minimum number; when reading a live capture, only one bufferful of packets is read at a time, so fewer than cnt packets may be processed.
A value of -1 or 0 for cnt causes all the packets received in one buffer to be processed when reading a live capture, and causes all the
packets in the file to be processed when reading a ``savefile''.
(In older versions of libpcap, the behavior when cnt was 0 was undefined; different platforms and devices behaved differently, so code that
must work with older versions of libpcap should use -1, nor 0, as the value of cnt.)
callback specifies a pcap_handler routine to be called with three arguments: a u_char pointer which is passed in the user argument to
pcap_loop() or pcap_dispatch(), a const struct pcap_pkthdr pointer pointing to the packet time stamp and lengths, and a const u_char
pointer to the first caplen (as given in the struct pcap_pkthdr a pointer to which is passed to the callback routine) bytes of data from
the packet. The struct pcap_pkthdr and the packet data are not to be freed by the callback routine, and are not guaranteed to be valid
after the callback routine returns; if the code needs them to be valid after the callback, it must make a copy of them.
RETURN VALUE
pcap_loop() returns 0 if cnt is exhausted, -1 if an error occurs, or -2 if the loop terminated due to a call to pcap_breakloop() before any
packets were processed. It does not return when live read timeouts occur; instead, it attempts to read more packets.
pcap_dispatch() returns the number of packets processed on success; this can be 0 if no packets were read from a live capture (if, for
example, they were discarded because they didn't pass the packet filter, or if, on platforms that support a read timeout that starts before
any packets arrive, the timeout expires before any packets arrive, or if the file descriptor for the capture device is in non-blocking mode
and no packets were available to be read) or if no more packets are available in a ``savefile.'' It returns -1 if an error occurs or -2 if
the loop terminated due to a call to pcap_breakloop() before any packets were processed. If your application uses pcap_breakloop(), make
sure that you explicitly check for -1 and -2, rather than just checking for a return value < 0.
If -1 is returned, pcap_geterr() or pcap_perror() may be called with p as an argument to fetch or display the error text.
SEE ALSO pcap(3PCAP), pcap_geterr(3PCAP), pcap_breakloop(3PCAP)
24 December 2008 PCAP_LOOP(3PCAP)