Advanced Bash−Scripting Guide

Advanced Bash−Scripting Guide
grep −v '^#' | # Delete lines beginning with a hashmark.
grep −v '^$'
# Delete blank lines.
exit 0
Example A−10. Soundex conversion
#!/bin/bash
# soundex.sh: Calculate "soundex" code for names
# =======================================================
# Soundex script
# by
# Mendel Cooper
# thegrendel@theriver.com
# 23 January, 2002
#
# Placed in the Public Domain.
#
# A slightly different version of this script appeared in
#+ Ed Schaefer's July, 2002 "Shell Corner" column
#+ in "Unix Review" on−line,
#+ http://www.unixreview.com/documents/uni1026336632258/
# =======================================================
ARGCOUNT=1
E_WRONGARGS=70
# Need name as argument.
if [ $# −ne "$ARGCOUNT" ]
then
echo "Usage: `basename $0` name"
exit $E_WRONGARGS
fi
assign_value ()
# Assigns numerical value
{ #+ to letters of name.
val1=bfpv # 'b,f,p,v' = 1
val2=cgjkqsxz # 'c,g,j,k,q,s,x,z' = 2
val3=dt
# etc.
val4=l
val5=mn
val6=r
# Exceptionally clever use of 'tr' follows.
# Try to figure out what is going on here.
value=$( echo "$1" \
| tr −d wh \
| tr $val1 1 | tr $val2 2 | tr $val3 3 \
| tr $val4 4 | tr $val5 5 | tr $val6 6 \
| tr −s 123456 \
| tr −d aeiouy )
# Assign letter values.
# Remove duplicate numbers, except when separated by vowels.
# Ignore vowels, except as separators, so delete them last.
# Ignore 'w' and 'h', even as separators, so delete them first.
Appendix A. Contributed Scripts 377