Hi
$ a=10 ; b=2
$ expr $a + $b
12
$ expr $a - $b
8
$ expr $a / $b
5
$ expr $a * $b
expr: syntax error
Any idean why I am getting this error only when multiplying two numbers. Whats the exact syntax?
Thanks a lot to all in advance
CSaha (5 Replies)
Is there a way that i can get something like this to work:
Number=`expr 80 \* 10.69`
i.e. To multiply an integer by a decimal or a decimal by a decimal etc...?
thanks (10 Replies)
Im very new to programming. But I would like to write a script which extracts and multiply values from 2 txt and output as a new file. Can someone please teach me how to write it? Thank you so much
for example
File A File B
1 34 1 2
2 13 2 2
3 8 3 3
File C output
1 68
2... (2 Replies)
if i declare both but don't input any variables what values will the int array and file pointer array have on default, and if i want to reset any of the elements of both arrays to default, should i just set it to 0 or NULL or what? (1 Reply)
Hi, this is my code.It's simple : there are 2 2D arrays and the multiplied to C.
#include<stdio.h>
#include<sys/shm.h>
#include<sys/stat.h>
#include<stdlib.h>
main()
{
int *A; //A
int *B; //B
int *C; //C
int i,j,x,k,d;
int id;
... (17 Replies)
hello,
I'm writing a php script in fedora to run with a csv file. I want the script to read column 4 and multiply each single line in the column by 1000, how would that script look? I've written one script but it's obviously incorrect because it will not execute the command.
here is my... (4 Replies)
I am trying to take all the elements of an array and multiply them by 2, and then copy them to a new array. Here is what I have
i=0
for true in DMGLIST
do
let DMGSIZES2="${DMGSIZES}"*2
let i++
done
unset i
echo ${DMGSIZES2}
It does the calculation correctly for the first element,... (7 Replies)
I have 2 files, that look like this:
ID SNP1 SNP2 SNP3 SNP4
A1 1 2 0 2
A2 2 0 1 1
A3 0 2 NA 1
A4 1 1 0 2
and this:
SNP score
SNP1 0.5
SNP2 0.7
SNP3 0.8
SNP4 0.2
Basically, all of the SNP-values are 0,1, 2 or NA, and they each have a score, listed in the second file. The total... (5 Replies)
Hi Experts,
Please help with the following.
I have 3 columns in File 1 , variables with values nested within groups.
File 1
gr1 var1 a
gr1 var2 b
gr1 var3 a
gr1 var4 c
gr2 var1 a
gr2 var2 a
gr2 var4 c
gr3 var1 b
gr3 var3 b
gr3 var4 a
gr3 var5 a (3 Replies)
I am trying to remove the last letter in a file and then multiply each line (which contained this letter) by 500. This is what I have:
1499998A
1222222A
1325804A
1254556
1235
9998
777
cat /tmp/listzz |gawk '{print $4}'|gawk '{gsub(//, ""); print } This removes the A... (1 Reply)
Discussion started by: newbie2010
1 Replies
LEARN ABOUT OPENDARWIN
pthread_atfork
PTHREAD_ATFORK(3) Library Functions Manual PTHREAD_ATFORK(3)NAME
pthread_atfork - register handlers to be called at fork(2) time
SYNOPSIS
#include <pthread.h>
int pthread_atfork(void (*prepare)(void), void (*parent)(void), void (*child)(void));
DESCRIPTION
pthread_atfork registers handler functions to be called just before and just after a new process is created with fork(2). The prepare han-
dler will be called from the parent process, just before the new process is created. The parent handler will be called from the parent
process, just before fork(2) returns. The child handler will be called from the child process, just before fork(2) returns.
One or several of the three handlers prepare, parent and child can be given as NULL, meaning that no handler needs to be called at the cor-
responding point.
pthread_atfork can be called several times to install several sets of handlers. At fork(2) time, the prepare handlers are called in LIFO
order (last added with pthread_atfork, first called before fork), while the parent and child handlers are called in FIFO order (first
added, first called).
To understand the purpose of pthread_atfork, recall that fork(2) duplicates the whole memory space, including mutexes in their current
locking state, but only the calling thread: other threads are not running in the child process. The mutexes are not usable after the fork
and must be initialized with pthread_mutex_init in the child process. This is a limitation of the current implementation and might or
might not be present in future versions.
RETURN VALUE
pthread_atfork returns 0 on success and a non-zero error code on error.
ERRORS
ENOMEM insufficient memory available to register the handlers.
AUTHOR
Xavier Leroy <Xavier.Leroy@inria.fr>
SEE ALSO fork(2), pthread_mutex_lock(3), pthread_mutex_unlock(3).
LinuxThreads PTHREAD_ATFORK(3)