S_ISDIR is simply a macro which checks the mode of a file to see whether the file is a directory. If so it returns true. Have a look in stat.h for more information.
Hallo
I want write a sh script but I have some troubles!
How can I write the Return value to a variable? I need an egrep command with the option -c, how many times it give the pattern. This return value shold be written in a variable.
Could you help me? (1 Reply)
hi
iam reading data from web page using request socket and curl socket.
now my problem is some the web page containg data as a image so how can i read the data from a image.
thank,inadvance.
sree (3 Replies)
Hi All,
Can anyone please let me know the syntax / how to pick up the Return Code ( RC) from the mailx command and return it to SAS uisng 'system()' function and '${?}'.
I am in a process to send the mail automatically with an attachment to bulk users. I have used 'Mailx' and 'Unencode'... (0 Replies)
Hi guys,
I am newbie in unix, so I need your help.
I need to right unix function code that can read sample.txt. If sample.txt contains sentence such as "Error due to syntax." then it will return value.
I tried below code, but I got errors.
if
then
echo " There are... (4 Replies)
ls xx > yy.log
echo $? can get the return value of "ls xx"
but if I use
ls xx |tee -a yy.log
I can't get the return value of "ls xx", and I get the return value of the whole cmd "ls xx |tee -a yy.log", it is always "0"
my question is how could I get the return value of "ls xx"... (1 Reply)
I am using the popular bash shell.
Under the current interactive shell, i run the script like:
". ./myscript.txt" . After the current shell has finish the script, the shell will continue to work as I did previously. Actually I want the shell can return from the middle of the scripts it is... (1 Reply)
Not sure where the problem is. I can run the script without any issue using the following command.
. /opt/app/scripts/cdc_migration.sh
But it fails with the below error when I try it this way
/opt/app/scripts/cdc_migration.sh
/opt/app/scripts/cdc_migration.sh: line 65: return: can only... (1 Reply)
Discussion started by: svajhala
1 Replies
LEARN ABOUT X11R4
pcap_breakloop
PCAP_BREAKLOOP(3PCAP)PCAP_BREAKLOOP(3PCAP)NAME
pcap_breakloop - force a pcap_dispatch() or pcap_loop() call to return
SYNOPSIS
#include <pcap/pcap.h>
void pcap_breakloop(pcap_t *);
DESCRIPTION
pcap_breakloop() sets a flag that will force pcap_dispatch() or pcap_loop() to return rather than looping; they will return the number of
packets that have been processed so far, or -2 if no packets have been processed so far.
This routine is safe to use inside a signal handler on UNIX or a console control handler on Windows, as it merely sets a flag that is
checked within the loop.
The flag is checked in loops reading packets from the OS - a signal by itself will not necessarily terminate those loops - as well as in
loops processing a set of packets returned by the OS. Note that if you are catching signals on UNIX systems that support restarting system
calls after a signal, and calling pcap_breakloop() in the signal handler, you must specify, when catching those signals, that system calls
should NOT be restarted by that signal. Otherwise, if the signal interrupted a call reading packets in a live capture, when your signal
handler returns after calling pcap_breakloop(), the call will be restarted, and the loop will not terminate until more packets arrive and
the call completes.
Note also that, in a multi-threaded application, if one thread is blocked in pcap_dispatch(), pcap_loop(), pcap_next(), or pcap_next_ex(),
a call to pcap_breakloop() in a different thread will not unblock that thread; you will need to use whatever mechanism the OS provides for
breaking a thread out of blocking calls in order to unblock the thread, such as thread cancellation in systems that support POSIX threads.
Note that pcap_next() and pcap_next_ex() will, on some platforms, loop reading packets from the OS; that loop will not necessarily be ter-
minated by a signal, so pcap_breakloop() should be used to terminate packet processing even if pcap_next() or pcap_next_ex() is being used.
pcap_breakloop() does not guarantee that no further packets will be processed by pcap_dispatch() or pcap_loop() after it is called; at most
one more packet might be processed.
If -2 is returned from pcap_dispatch() or pcap_loop(), the flag is cleared, so a subsequent call will resume reading packets. If a posi-
tive number is returned, the flag is not cleared, so a subsequent call will return -2 and clear the flag.
SEE ALSO pcap(3PCAP), pcap_loop(3PCAP), pcap_next_ex(3PCAP)
5 April 2008 PCAP_BREAKLOOP(3PCAP)