I would like to know how to pass a variable inside a variable to a function.
sample code below
--------------
for x in 1 9
do
check_null $C$x ##call function to check if the value is null
if
then
echo "line number:$var_cnt,... (2 Replies)
Hi All,
I need to pass a variable to perl script from bash script, where in perl i am using if condition. Here is the cmd what i am using in perl
FROM_DATE="06/05/2008"
TO_DATE="07/05/2008"
"perl -ne ' print if ( $_ >="$FROM_DATE" && $_ <= "$TO_DATE" ) ' filename"
filename has... (10 Replies)
Any help would be great. I know this is a dumb way of doing this, but I would like to know if there is a solution doing it this way. I'm very new at this and I'd like to learn more. Thanks! :D:D
count=0
while ; do
echo "enter your name"
read name_$count
let count=count+1
done
... (2 Replies)
Hi everybody,
Firstly, this would be the first time I'm using JavaScript. My background is mainly Perl. Nevertheless, here's my problem.
So I've created a function
function linkout(url){
setTimeout("window.open(url)",5000) //in milliseconds
}
However because the variable "url" is... (0 Replies)
Not sure if this is the right place to ask this but here goes. I am creating a cheat sheet for co-workers. The concept is that you pick wire size and conduit size and the amount of wires that will fit is displayed. I haven't used alot of drop downs and can't quite figure out the way the get id... (3 Replies)
Would really appreciate it if someone could point out my mistake in this line of code, i've been staring blankly at it trying everything i can think of some time now and coming up with nothing.
#!/bin/bash
echo "Enter Username"
read Username
awk -F: -v var=${Username} '/^var:/... (9 Replies)
I'm trying to write a basic bash script that takes input you give (what directory, if any, what name, if any ....) and passes the information to find.
I'm trying to just create a string with all variables and then pass it to find. So far I have this extremely simple:
#!/bin/bash -f
... (2 Replies)
I have a below syntax its working fine...
var12=$(ps -ef | grep apache | awk '{print $2,$4}')
Im getting expected output as below:
printf "%b\n" "${VAR12}"
dell 123
dell 456
dell 457
Now I wrote a while loop.. the output of VAR12 should be passed as input parameters to while loop and results... (5 Replies)
Hi All,
I need to pass a variable from bash script to perl script and in the perl script i am using those variables in the sql query but its giving
error :
Use of uninitialized value $ENV{"COUNTRYCD"} in concatenation (.) or string at /GIS_ROOT/custom/tables/DBread_vendor.pl line 50.
Can ... (6 Replies)
I am totally new to PHP and I am trying to create a script that will as a user for a hostname and then use the "hostname" variable to generate a report using REST API.
I am able to create the html script and php script to GET the "hostname" but I am having trouble passing the hostname variable... (10 Replies)
Discussion started by: kieranfoley
10 Replies
LEARN ABOUT FREEBSD
counter_enter
COUNTER(9) BSD Kernel Developer's Manual COUNTER(9)NAME
counter -- SMP-friendly kernel counter implementation
SYNOPSIS
#include <sys/types.h>
#include <sys/systm.h>
#include <sys/counter.h>
counter_u64_t
counter_u64_alloc(int wait);
void
counter_u64_free(counter_u64_t c);
void
counter_u64_add(counter_u64_t c, int64_t v);
void
counter_enter();
void
counter_exit();
void
counter_u64_add_protected(counter_u64_t c, int64_t v);
uint64_t
counter_u64_fetch(counter_u64_t c);
void
counter_u64_zero(counter_u64_t c);
#include <sys/sysctl.h>
SYSCTL_COUNTER_U64(parent, nbr, name, access, ptr, descr);
SYSCTL_ADD_COUNTER_U64(ctx, parent, nbr, name, access, ptr, descr);
DESCRIPTION
counter is a generic facility to create counters that can be utilized for any purpose (such as collecting statistical data). A counter is
guaranteed to be lossless when several kernel threads do simultaneous updates. However, counter does not block the calling thread, also no
atomic(9) operations are used for the update, therefore the counters can be used in any non-interrupt context. Moreover, counter has special
optimisations for SMP environments, making counter update faster than simple arithmetic on the global variable. Thus counter is considered
suitable for accounting in the performance-critical code pathes.
counter_u64_alloc(wait)
Allocate a new 64-bit unsigned counter. The wait argument is the malloc(9) wait flag, should be either M_NOWAIT or M_WAITOK. If
M_NOWAIT is specified the operation may fail.
counter_u64_free(c)
Free the previously allocated counter c.
counter_u64_add(c, v)
Add v to c. The KPI does not guarantee any protection from wraparound.
counter_enter()
Enter mode that would allow to safely update several counters via counter_u64_add_protected(). On some machines this expands to
critical(9) section, while on other is a nop. See IMPLEMENTATION DETAILS.
counter_exit()
Exit mode for updating several counters.
counter_u64_add_protected(c, v)
Same as counter_u64_add(), but should be preceded by counter_enter().
counter_u64_fetch(c)
Take a snapshot of counter c. The data obtained is not guaranteed to reflect the real cumulative value for any moment.
counter_u64_zero(c)
Clear the counter c and set it to zero.
SYSCTL_COUNTER_U64(parent, nbr, name, access, ptr, descr)
Declare a static sysctl oid that would represent a counter. The ptr argument should be a pointer to allocated counter_u64_t. A read
of the oid returns value obtained through counter_u64_fetch(). Any write to the oid zeroes it.
SYSCTL_ADD_COUNTER_U64(ctx, parent, nbr, name, access, ptr, descr)
Create a sysctl oid that would represent a counter. The ptr argument should be a pointer to allocated counter_u64_t. A read of the
oid returns value obtained through counter_u64_fetch(). Any write to the oid zeroes it.
IMPLEMENTATION DETAILS
On all architectures counter is implemented using per-CPU data fields that are specially aligned in memory, to avoid inter-CPU bus traffic
due to shared use of the variables between CPUs. These are allocated using UMA_ZONE_PCPU uma(9) zone. The update operation only touches the
field that is private to current CPU. Fetch operation loops through all per-CPU fields and obtains a snapshot sum of all fields.
On amd64 a counter update is implemented as a single instruction without lock semantics, operating on the private data for the current CPU,
which is safe against preemption and interrupts.
On i386 architecture, when machine supports the cmpxchg8 instruction, this instruction is used. The multi-instruction sequence provides the
same guarantees as the amd64 single-instruction implementation.
On some architectures updating a counter require a critical(9) section.
SEE ALSO atomic(9), critical(9), locking(9), malloc(9), sysctl(9), uma(9)HISTORY
The counter facility first appeared in FreeBSD 10.0.
AUTHORS
The counter facility was written by Gleb Smirnoff and Konstantin Belousov.
BSD February 7, 2014 BSD