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Incrementing ascii values

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# 1  
Old 02-17-2011
Question Incrementing ascii values

Hi All,

I require some help with the below:

I am trying to incriment the ascii value of a letter and then print it.

So basically "a" becomes "b" and "z" becomes "A".

Does anyone have any pointers?


# 2  
Old 02-17-2011
Like this?
echo This is Something z write home aboutZ | tr 'a-zA-Z' 'b-zA-Za'
Uijt jt Tpnfuijoh A xsjuf ipnf bcpvua

# 3  
Old 02-17-2011
#include <stdio.h>

int main(int argc, char **argv ) {
  if ( *argv[1] == 'z' ) *argv[1]=64;
  printf( "%c\n", *argv[1]+1 );
  return 0;

$ cc -o mytest mypoorc.c

$ ./mytest a

$ ./mytest o

$ ./mytest z

This User Gave Thanks to Scott For This Post:
# 4  
Old 02-17-2011
Originally Posted by bParks
... incriment the ascii value of a letter and then print it.

So basically "a" becomes "b" and "z" becomes "A".


$ echo "abcdefghijklmnopqrstuvwxyz" | perl -plne 'tr/a-yz/b-zA/'

# 5  
Old 02-17-2011
Originally Posted by apmcd47
Like this?
echo This is Something z write home aboutZ | tr 'a-zA-Z' 'b-zA-Za'
Uijt jt Tpnfuijoh A xsjuf ipnf bcpvua

Depending on the locale settings, this may or may not do what you expect. For example, in an en_US.UTF-8 locale, a-z expands to aBbCc...YyZz. a-z and A-Z are almost identical in such a locale; a-z covers all letters except for "A", and A-Z covers all letters except for "z".

It's a good idea to explicitly set the applicable locale environment variables in the script when using range expressions.


P.S. While helping to troubleshoot a script a while back, this particular "feature" claimed an hour of my life. NEVER AGAIN! Smilie

Last edited by alister; 02-17-2011 at 06:02 PM..
# 6  
Old 02-17-2011
Sorry all I should have been more specific,

The aim is to be able to shift the letters via an inputed variable not just one possition.

Unfortunatly c is out of the question so ksh is the form that i require the code to be in.

Thanks for you assistance,
# 7  
Old 02-17-2011
echo 'a' | nawk -f parks.awk 
echo 'a' | nawk -v shift=4 -f parks.awk

function initascii2dec()
  for(i=0;i<=255;i++) {
    ch=sprintf("%c", i)
    ascii2dec[ch] = i
  if (!shift) shift=1
  printf("%c\n", ascii2dec[$1]+shift)

Last edited by vgersh99; 02-17-2011 at 08:37 PM..
This User Gave Thanks to vgersh99 For This Post:

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