Tag: Pattern matching

function sr() {

declare pattern replacement name usage
declare -i pvar=0 rvar=0 tvar=0

usage=\'usage: sr [-t ] [-n name] [-p pattern] [-r replacement] [-- ] [dir1 dir2 ...]\'

# cf. http://bsdpants.blogspot.com/2007/02/option-ize-your-shell-scripts.html

while [[ \"${1:0:1}\" == \'-\' ]] ; do

[[ \"${1}\" == \'--\' ]] && { shift; break; } # -- marks end of options

[[ ${#1} -ne 2 ]] && { echo \"${usage}\"; return 1; }

case \"${1:1:1}\" in
\'n\') name=\"${2}\"
shift 2 ;;
\'p\') pattern=\"${2}\"
pvar=1
shift 2 ;;
\'r\') replacement=\"${2}\"
rvar=1
shift 2 ;;
\'t\') tvar=1
shift ;;
*) echo \"${usage}\"
return 1 ;;
esac

done

if [[ $pvar -eq 0 ]] || [[ $rvar -eq 0 ]]; then
echo \'Both options -p and -r must be specified!\'
echo \"${usage}\"
return 1
fi

while read -d $\'\' fpath; do

if [[ -z \"$(/usr/bin/egrep -I -m1 \'^.\' \"${fpath}\")\" ]]; then # skip binary files
echo \"Binary file: ${fpath}\"
continue
fi

if [[ $tvar -eq 0 ]]; then # perform an actual search & replace

cat <<-EOF | /bin/ed -s \"${fpath}\"
H
g/${pattern}/s/${pattern}/${replacement}/g
wq
EOF

else # only simulate a search & replace and print the result to stdout

printf \"nn33[1m%s33[mnnn\" \"${fpath}\" # print the current file path

# delete all lines that do not contain a pattern match: v/...
# add a final trailing new line in case all lines got deleted: $a...
# do the matching: g/${pattern}/...
# insert \'#: \' at the beginning of each line: g/./s/(...

cat <<-EOF | /bin/ed -s \"${fpath}\"
H
v/${pattern}/d
$a

.
g/${pattern}/s/${pattern}/$(printf \"33[32m${replacement}33[m\")/g
g/./s/(.*)/#: 1/g
,p
EOF

fi

done < <(/usr/bin/find -x \"${@}\" -type f -name \"*${name}\" -not -empty -print0)

}

man ed | less -p \'REGULAR EXPRESSIONS\'

# test mode
sr -t -p hello -r world -n \".txt\" /path/to/dir | less -r

# actual search & replace without previous backup
sr -p hello -r world -n \".txt\" /path/to/dir

# backslash-escape the / character
sr -t -p \'/usr/local\' -r \'/opt/local\' /path/to/file

URL: http://snippets.dzone.com/posts/show/10695

Related articles by Zemanta

• Guide to Regular Expressions in Java (Part 1) (nofluffjuststuff.com)
• Mod and hack the GNome main menu with automated scripts to create a menu of the directory. (amit-agarwal.co.in)