Math routines (was bourne shell query)
Jeffrey Gleixner
glex at uh.msc.umn.edu
Mon Sep 3 00:16:01 AEST 1990
In article <75 at iconsys>, mday at iconsys (Matt Day) writes:
> In article <SCOTT.90Aug30124930 at tab00.larc.nasa.gov>
scott at tab00.larc.nasa.gov (Scott Yelich) writes:
> >As a side question, does ANYONE have any bourne shell routines which do
> >math... reasonably effeciently? (For numbers > 1000?)
>
> For the Bourne shell, the most efficient way to do math is to use the "expr"
> ... If you have a shell script that needs to do
> a lot of math, I suggest you use the C shell built in math operators; it's
If you're going to do a lot of math write a {your favorite language besides
*sh here} program to do the math for you. Even if you're doing a small
amount of math it will really speed it up.
i.e.
#!/bin/sh
count 1 6 | while read value ; do
some commands...
done
=========
/*
* Count.c
*
* print succesive numbers from start to end.
* Used in scripts instead of `expr $i +1`
*/
#include <stdio.h>
main(argc,argv)
int argc; char *argv[];
{
register int i,j;
i=atoi(argv[1]);
j=atoi(argv[2]);
while (i <= j)
printf(" %d",i++);
}
--
glex at msc.umn.edu === " I don't go out with girls that say bitch'n " ===
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