Advanced Bash−Scripting Guide

Advanced Bash−Scripting Guide
fi
( shift; "$PROGNAME" $* ) | grep $1
# Script recursively calls itself.
exit 0
# Script exits here.
# It's o.k. to put non−hashmarked comments
#+ and data after this point.
# −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−
# Sample "phonebook" datafile:
John Doe 1555 Main St., Baltimore, MD 21228 (410) 222−3333
Mary Moe 9899 Jones Blvd., Warren, NH 03787 (603) 898−3232
Richard Roe 856 E. 7th St., New York, NY 10009 (212) 333−4567
Sam Roe 956 E. 8th St., New York, NY 10009 (212) 444−5678
Zoe Zenobia 4481 N. Baker St., San Franciso, SF 94338 (415) 501−1631
# −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−
$bash pb.sh Roe
Richard Roe 856 E. 7th St., New York, NY 10009 (212) 333−4567
Sam Roe 956 E. 8th St., New York, NY 10009 (212) 444−5678
$bash pb.sh Roe Sam
Sam Roe 956 E. 8th St., New York, NY 10009 (212) 444−5678
# When more than one argument passed to script,
#+ prints *only* the line(s) containing all the arguments.
Too many levels of recursion can exhaust the script's stack space, causing a segfault.
34.5. "Colorizing" Scripts
The ANSI [64] escape sequences set screen attributes, such as bold text, and color of foreground and
background. DOS batch files commonly used ANSI escape codes for color output, and so can Bash scripts.
Example 34−8. A "colorized" address database
#!/bin/bash
# ex30a.sh: "Colorized" version of ex30.sh.
# Crude address database
clear
# Clear the screen.
echo −n " "
echo −e '\E[37;44m'"\033[1mContact List\033[0m"
# White on blue background
echo; echo
echo −e "\033[1mChoose one of the following persons:\033[0m"
# Bold
tput sgr0
echo "(Enter only the first letter of name.)"
echo
echo −en '\E[47;34m'"\033[1mE\033[0m" # Blue
tput sgr0
# Reset colors to "normal."
echo "vans, Roland"
# "[E]vans, Roland"
echo −en '\E[47;35m'"\033[1mJ\033[0m" # Magenta
Chapter 34. Miscellany 342