10 More Discussions You Might Find Interesting
1. Shell Programming and Scripting
Hello! Before you "bash" me with
- Not another post of this kind
Please read on and you will understand my problem...
I am using the below to extract a sum of the diskIO on a Solaris server.
#!/bin/sh
PATH=/usr/bin:/usr/sbin:/sbin; export PATH
TEMP1="/tmp/raw-sar-output.txt$$"... (3 Replies)
Discussion started by: haaru
3 Replies
2. Shell Programming and Scripting
Hi,
I use Korn Shell. Searched Forum and modified the way the file is input to the while loop, but still the variable does not seem to be retaining the final count.
while read name
do
Tmp=`echo $name | awk '{print $9 }'`
Count=`cat $Tmp | wc -l`... (6 Replies)
Discussion started by: justchill
6 Replies
3. Shell Programming and Scripting
I am trying to use bc to calculate the difference between two nano second time stamps. bc does the calculation but seems to ignore the scale option:
micro_start=$(date +%s.%N)
# .. some stuff happens here
micro_stop=$(date +%s.%N)
TOT=$(echo "scale=3; $micro_stop - $micro_start" | bc)... (2 Replies)
Discussion started by: LostInTheWoods
2 Replies
4. Shell Programming and Scripting
Friends,
I am using ksh under SunoS. This is what I have
In file1.sh
NOW=$(date +"%b-%d-%y")
LOGFILE="./log-$NOW.log"
I will be using this file through file1.sh as log file.
I have another script file2.sh which is being called inside my file1.sh. I would like to use the same log... (6 Replies)
Discussion started by: dahlia84
6 Replies
5. AIX
Hello All,
I am getting this error while compiling my application on IBM AIX 5.3.
As I tried to define _XOPEN_SOURCE=500 in makefile, that didn't work.
Please help us to resolve the error. (0 Replies)
Discussion started by: mustus
0 Replies
6. Shell Programming and Scripting
Hi,
I want to know about the variable scope in shell script.
How can we use the script argument inside the function?
fn () {
echo $1 ## I want this argument should be the main script argument and not the funtion argument.
}
also are there any local,global types in shell script?
if... (3 Replies)
Discussion started by: shellwell
3 Replies
7. Shell Programming and Scripting
Hi All,
I am new to unix shell scripting,
in the below script "num" is an input file which contains a series of numbers example :
2
3
5
8
I want to add the above all numbers and want the result finally outside the while loop. it prints the value zero instead of the actual expected... (13 Replies)
Discussion started by: nagnatar
13 Replies
8. Shell Programming and Scripting
Hi ,
I'm trying to change the variable value in a while loop , however its not working it seems that the problem with subshells while reading the file.
#!/bin/sh
FLAG=0;
cat filename | while read data
do
FLAG=1;
done
echo $FLAG
Should display 1 instead displays 0 (13 Replies)
Discussion started by: dinjo_jo
13 Replies
9. AIX
What is the scope of AIX as I am starting my career as a fresher in AIX administration?? (4 Replies)
Discussion started by: abhishek27
4 Replies
10. Programming
I'm having a problem getting this to work..
I got 3 files,
start.C - Where i got my main() function
Menu.C & Menu.h - Where I'm trying to use hash_map
start.C
#include <iostream>
#include "Menu.h"
using namespace std;
int main() { /* test code here */ return 0; }
Menu.h ... (1 Reply)
Discussion started by: J.P
1 Replies
condition(5) Standards, Environments, and Macros condition(5)
NAME
condition - concepts related to condition variables
DESCRIPTION
Occasionally, a thread running within a mutex needs to wait for an event, in which case it blocks or sleeps. When a thread is waiting for
another thread to communicate its disposition, it uses a condition variable in conjunction with a mutex. Although a mutex is exclusive and
the code it protects is sharable (at certain moments), condition variables enable the synchronization of differing events that share a
mutex, but not necessarily data. Several condition variables may be used by threads to signal each other when a task is complete, which
then allows the next waiting thread to take ownership of the mutex.
A condition variable enables threads to atomically block and test the condition under the protection of a mutual exclusion lock (mutex)
until the condition is satisfied. If the condition is false, a thread blocks on a condition variable and atomically releases the mutex that
is waiting for the condition to change. If another thread changes the condition, it may wake up waiting threads by signaling the associated
condition variable. The waiting threads, upon awakening, reacquire the mutex and re-evaluate the condition.
Initialize
Condition variables and mutexes should be global. Condition variables that are allocated in writable memory can synchronize threads among
processes if they are shared by the cooperating processes (see mmap(2)) and are initialized for this purpose.
The scope of a condition variable is either intra-process or inter-process. This is dependent upon whether the argument is passed implic-
itly or explicitly to the initialization of that condition variable. A condition variable does not need to be explicitly initialized. A
condition variable is initialized with all zeros, by default, and its scope is set to within the calling process. For inter-process syn-
chronization, a condition variable must be initialized once, and only once, before use.
A condition variable must not be simultaneously initialized by multiple threads or re-initialized while in use by other threads.
Condition variables attributes may be set to the default or customized at initialization. POSIX threads even allow the default values to
be customized. Establishing these attributes varies depending upon whether POSIX or Solaris threads are used. Similar to the distinctions
between POSIX and Solaris thread creation, POSIX condition variables implement the default, intra-process, unless an attribute object is
modified for inter-process prior to the initialization of the condition variable. Solaris condition variables also implement as the
default, intra-process; however, they set this attribute according to the argument, type, passed to their initialization function.
Condition Wait
The condition wait interface allows a thread to wait for a condition and atomically release the associated mutex that it needs to hold to
check the condition. The thread waits for another thread to make the condition true and that thread's resulting call to signal and wakeup
the waiting thread.
Condition Signaling
A condition signal allows a thread to unblock the next thread waiting on the condition variable, whereas, a condition broadcast allows a
thread to unblock all threads waiting on the condition variable.
Destroy
The condition destroy functions destroy any state, but not the space, associated with the condition variable.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
+-----------------------------+-----------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+-----------------------------+-----------------------------+
|MT-Level |MT-Safe |
+-----------------------------+-----------------------------+
SEE ALSO
fork(2), mmap(2), setitimer(2), shmop(2), cond_broadcast(3C), cond_destroy(3C), cond_init(3C), cond_signal(3C), cond_timedwait(3C),
cond_wait(3C), pthread_cond_broadcast(3C), pthread_cond_destroy(3C), pthread_cond_init(3C), pthread_cond_signal(3C), pthread_cond_timed-
wait(3C), pthread_cond_wait(3C), pthread_condattr_init(3C), signal(3C), attributes(5), mutex(5), standards(5)
NOTES
If more than one thread is blocked on a condition variable, the order in which threads are unblocked is determined by the scheduling pol-
icy.
USYNC_THREAD does not support multiple mapplings to the same logical synch object. If you need to mmap() a synch object to different loca-
tions within the same address space, then the synch object should be initialized as a shared object USYNC_PROCESS for Solaris, and
PTHREAD_PROCESS_PRIVATE for POSIX.
SunOS 5.10 20 Jul 1998 condition(5)