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Top Forums Shell Programming and Scripting $RANDOM does not work inside a shell script Post 302437730 by DeCoTwc on Friday 16th of July 2010 03:36:28 AM
Old 07-16-2010
In Ubuntu sh is symlinked to dash.

Code:
d@DeCoBuntu:~$ ls  -ltrh /bin/sh
lrwxrwxrwx 1 root root 4 2010-05-26 02:41 /bin/sh -> dash
d@DeCoBuntu:~$ ^C

however, if you're just looking for some random numbers and letters, you can do this in pretty much any shell:

Code:
d@DeCoBuntu:~$ type rand
rand is a function
rand () 
{ 
    tr -dc _A-Z-a-z-0-9 < /dev/urandom | head -c$1;
    echo
}

Less efficient, but it'll get the job done.
 

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rand(3UCB)					     SunOS/BSD Compatibility Library Functions						rand(3UCB)

NAME
rand, srand - simple random number generator SYNOPSIS
/usr/ucb/cc[ flag ... ] file ... int rand() int srand( seed); unsigned seed; DESCRIPTION
rand() uses a multiplicative congruential random number generator with period 2**32 to return successive pseudo-random numbers in the range from 0 to "2**31 -1." srand() can be called at any time to reset the random-number generator to a random starting point. The generator is initially seeded with a value of 1. SEE ALSO
drand48(3C), rand(3C), random(3C) NOTES
Use of these interfaces should be restricted to only applications written on BSD platforms. Use of these interfaces with any of the system libraries or in multi-thread applications is unsupported. The spectral properties of rand() leave a great deal to be desired. drand48(3C) and random(3C) provide much better, though more elaborate, random-number generators. The low bits of the numbers generated are not very random; use the middle bits. In particular the lowest bit alternates between 0 and 1. SunOS 5.10 12 Feb 1993 rand(3UCB)
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