I’m looking for a shell command (a one-liner) that eats all of its standard input if that input matches a string. Otherwise, it just outputs its input.
Likewise, how about a command that eats all of its input if it doesn’t match the string.
Presumably sed or awk can do it, but it’s beyond my fu. I can easily do it with a shell script but I’d prefer a single command.
This is useful in crontab so that you only receive an email if the output of a command fails (i.e. matches a string).
So, below, what are “eatIfMatch” and “eatIfNoMatch”?
Thanks for any ideas.
$ cat matchFile
This file
will match the
pattern
$ cat noMatchFile
This file
doesn’t quite
Match
though
$ eatIfMatch match < matchFile
$ eatIfMatch match < noMatchFile
This file
doesn’t quite
Match
though
$ eatIfNoMatch match < matchFile
This file
will match the
pattern
$ eatIfNoMatch match < noMatchFile
$
This might work for you (GNU sed and Bash):
eatIfMatch(){ sed -zn '/'"$1"'/!p' "$2"; }
eatIfMatch match fileMatch
eatIfMatch match fileNoMatch
This file
doesn’t quite
Match
though
eatIfNoMatch(){ sed -zn '/'"$1"'/p' "$2"; }
eatIfNoMatch match fileMatch
This file
will match the
pattern
eatIfNoMatch match fileNoMatch
Function eatIfMatch accepts regexp to match and if it does eats the file.
Function eatIfNoMatch accepts regexp to mat and if it does not eats file.
Assign the input to a variable. Check if the variable contains the string. If not, it prints the string.
eatIfMatch() {
local var=$(cat)
if [[ $var != *"$1"* ]]
then printf "%s\n" "$var"
fi
}
If you want awk, it's essentially the same logic
awk '/match/ {found=1} {all = all "\n" $0} END {if(found) print substr(all, 1)}'
Related
I have a string value stored in a variable:
PTYPE="Other Farm|Raised Ranch|Farm house|Other|A-Frame|Log Home"
I want to find & replace Other with some value like NOTHING. All values are stored in variables.
WhatToChange=Other
NewValue=NOTHING
echo $PTYPE|sed -e "s#${WhatToChange}#${NewValue}#g"
This is replacing all the occurances of Other and getting output like:
NOTHING Farm|Raised Ranch|Farm house|NOTHING|A-Frame|Log Home
Is there any way I can exactly change only the exact one? The place for ${WhatToChange} is variable.
As you have well defined fields and want an exact match, awk could be easier to use than sed; at the very least, you won't have to worry about escaping the strings for using it in the sed expression:
echo "Other Farm|Raised Ranch|Farm house|Other|A-Frame|Log Home" |
awk -v old="Other" -v new="NOTHING" \
'BEGIN {FS = OFS = "|"} {for(i=1;i<=NF;i++) if($i == old) $i = new} 1'
output:
Other Farm|Raised Ranch|Farm house|NOTHING|A-Frame|Log Home
To match either the exact character | or the beginning of the line, use ([|]|^).
To match either the exact character | or the end of the line, use ([|]|$).
To put a | back in place only when appropriate, store these in match groups, and refer to those groups with \1 or \2:
PTYPE="Other Farm|Raised Ranch|Farm house|Other|A-Frame|Log Home"
WhatToChange=Other
NewValue=NOTHING
sed -re "s#(^|[|])${WhatToChange}($|[|])#\1${NewValue}\2#g" <<<"$PTYPE"
...emits as output:
Other Farm|Raised Ranch|Farm house|NOTHING|A-Frame|Log Home
...and still works even if WhatToChange is matched at the beginning or end of the list.
For fun, some perl:
This is like #Charles's sed solution: Note the \Q...\E so that the "to change" value is treated as literal text.
echo "$PTYPE" | perl -spe '
s{ (?:^|\|)\K \Q$WhatToChange\E (?=\||$) }{$NewValue}gx
' -- -WhatToChange=Other -NewValue=NOTHING
This is like #Fravadona's awk solution:
echo "$PTYPE" | perl -F'[|]' -sane '
print join "|", map {$_ eq $WhatToChange ? $NewValue : $_} #F
' -- -WhatToChange=Other -NewValue=NOTHING
How about
echo ${PTYPE//$WhatToChange/$NewValue}
UPDATE:
I just realized that the replacement should happen only if WhatToChange is the whole content between two separators (|). In this case, we can do it in bash as well (without the need to revert to a child process):
if [[ $PTYPE =~ (.*[|]|^)$WhatToChange([|].*|$) ]]
echo "${BASH_REMATCH[1]}${NewValue}${BASH_REMATCH[2]}"
fi
UPDATE (based on the comment by Fravadona):
Used in this way, WhatToChange is interpreted as a regular expression. This can be useful, if you want to catch for instance variations of the string, for instance
WhatToChange='[Oo]ther' # to catch Other and other
If you always want to have a literal match, you have to quote the variable:
[[ $PTYPE =~ (.*[|]|^)"$WhatToChange"([|].*|$) ]]
This might work for you (GNU sed & bash):
<<<"$PTYPE" sed 'y/|/\n/;s/^'"$WhatToChange"'$/'"$NewValue"'/mg;y/\n/|/'
Input $PTYPE as a here-string into sed.
Translate | separators to newlines.
Replace $WhatToChange to $NewValue for each matched line.
Translate newlines back to |'s.
N.B. The use of the m flag in the substitution command allows sed to work in multiline mode and this presents each value between separators on its own line.
An alternative:
sed -z 'y/|/\x00/;s/^'"$WhatToChange"'$/'"$NewValue"'/mg;y/\x00/|/;' file
I have the following string:
|**barak**.version|2001.0132012031539|
in file text.txt.
I would like to replace it with the following:
|**barak**.version|2001.01.2012031541|
So I run:
sed -i "s/\|\*\*$module\*\*.version\|2001.0132012031539/|**$module**.version|$version/" text.txt
but the result is a duplicate instead of replacing:
|**barak**.version|2001.01.2012031541|**barak**.version|2001.0132012031539|
What am I doing wrong?
Here is the value for module and version:
$ echo $module
barak
$ echo $version
2001.01.2012031541
Assumptions:
lines of interest start and end with a pipe (|) and have one more pipe somewhere in the middle of the data
search is based solely on the value of ${module} existing between the 1st/2nd pipes in the data
we don't know what else may be between the 1st/2nd pipes
the version number is the only thing between the 2nd/3rd pipes
we don't know the version number that we'll be replacing
Sample data:
$ module='barak'
$ version='2001.01.2012031541'
$ cat text.txt
**barak**.version|2001.0132012031539| <<<=== leave this one alone
|**apple**.version|2001.0132012031539|
|**barak**.version|2001.0132012031539| <<<=== replace this one
|**chuck**.version|2001.0132012031539|
|**barak**.peanuts|2001.0132012031539| <<<=== replace this one
One sed solution with -Extended regex support enabled and making use of a capture group:
$ sed -E "s/^(\|[^|]*${module}[^|]*).*/\1|${version}|/" text.txt
Where:
\| - first occurrence (escaped pipe) tells sed we're dealing with a literal pipe; follow-on pipes will be treated as literal strings
^(\|[^|]*${module}[^|]*) - first capture group that starts at the beginning of the line, starts with a pipe, then some number of non-pipe characters, then the search pattern (${module}), then more non-pipe characters (continues up to next pipe character)
.* - matches rest of the line (which we're going to discard)
\1|${version}| - replace line with our first capture group, then a pipe, then the new replacement value (${version}), then the final pipe
The above generates:
**barak**.version|2001.0132012031539|
|**apple**.version|2001.0132012031539|
|**barak**.version|2001.01.2012031541| <<<=== replaced
|**chuck**.version|2001.0132012031539|
|**barak**.peanuts|2001.01.2012031541| <<<=== replaced
An awk alternative using GNU awk:
awk -v mod="$module" -v vers="$version" -F \| '{ OFS=FS;split($2,map,".");inmod=substr(map[1],3,length(map[1])-4);if (inmod==mod) { $3=vers } }1' file
Pass two variables mod and vers to awk using $module and $version. Set the field delimiter to |. Split the second field into array map using the split function and using . as the delimiter. Then strip the leading and ending "**" from the first index of the array to expose the module name as inmod using the substr function. Compare this to the mod variable and if there is a match, change the 3rd delimited field to the variable vers. Print the lines with short hand 1
Pipe is only special when you're using extended regular expressions: sed -E
There's no reason why you need extended here, stick with basic regex:
sed "
# for lines matching module.version
/|\*\*$module\*\*.version|/ {
# replace the version
s/|2001.0132012031539|/|$version|/
}
" text.txt
or as an unreadable one-liner
sed "/|\*\*$module\*\*.version|/ s/|2001.0132012031539|/|$version|/" text.txt
I'm trying to convert a string that has either - (hyphen) or _ (underscore) to Capital_Case string.
#!/usr/bin/env sh
function cap_case() {
[ $# -eq 1 ] || return 1;
_str=$1;
_capitalize=${_str//[-_]/_} | sed -E 's/(^|_)([a-zA-Z])/\u\2/g'
echo "Capitalize:"
echo $_capitalize
return 0
}
read string
echo $(cap_case $string)
But I don't get anything out.
First I am replacing any occurrence of - and _ with _ ${_str//[-_]/_}, and then I pipe that string to sed which finds the first letter, or _ as the first group, and then the letter after the first group in the second group, and I want to uppercase the found letter with \u\2. I tried with \U\2 but that didn't work as well.
I want the string some_string to become
Some_String
And string some-string to become
Some_String
I'm on a mac, using zsh if that is helpful.
EDIT: More generic solution here to make each field's first letter Capital.
echo "some_string_other" | awk -F"_" '{for(i=1;i<=NF;i++){$i=toupper(substr($i,1,1)) substr($i,2)}} 1' OFS="_"
Following awk may help you.
echo "some_string" | awk -F"_" '{$1=toupper(substr($1,1,1)) substr($1,2);$2=toupper(substr($2,1,1)) substr($2,2)} 1' OFS="_"
Output will be as follows.
echo "some_string" | awk -F"_" '{$1=toupper(substr($1,1,1)) substr($1,2);$2=toupper(substr($2,1,1)) substr($2,2)} 1' OFS="_"
Some_String
This being zsh, you don't need sed (or even a function, really):
$ s=some-string-bar
$ print ${(C)s:gs/-/_}
Some_String_Bar
The (C) flag capitalizes words (where "words" are defined as sequences of alphanumeric characters separated by other characters); :gs/-/_ replaces hyphens with underscores.
If you really want a function, it's cap_case () { print ${(C)1:gs/-/_} }.
pure bash:
#!/bin/bash
camel_case(){
local d display string
declare -a strings # = scope local
[ "$2" ] && d="$2" || d=" " # optional output delimiter
ifs_ini="$IFS"
IFS+='_-' # we keep initial IFS
strings=( "$1" ) # array
for string in ${strings[#]} ; do
display+="${string^}$d"
done
echo "${display%$d}"
IFS="$ifs_ini"
}
camel_case "some-string_here" "_"
camel_case "some-string_here some strings here" "+"
camel_case "some-string_here some strings here"
echo "$BASH_VERSION"
exit
output:
Some_String_Here
Some+String+Here+Some+Strings+Here
Some String Here Some Strings Here
4.4.18(1) release
You can try this gnu sed
echo 'some_other-string' | sed -E 's/(^.)/\u&/;s/[_-](.)/_\u\1/g'
Explains :
s/(^.)/\u&/
(^.) match the first char and \u& put the match in capital letter.
s/[_-](.)/_\u\1/g
[_-](.) capture a char preceded by _ or - and replace it by _ and the matched char in capital letter.
The g at the end tell sed to make the replacement for each char which meet the criteria
You didn't assign to _capitalize - you set a _capitalize environment variable for the empty command that you piped into sed.
You probably meant
_capitalize=$(<<<"${_str//[-_]/_}" sed -E 's/(^|_)([a-zA-Z])/\1\u\2/g')
Note also that ${//} isn't standard shell, so you really ought to specify an interpreter other than sh.
A simpler approach would be simply:
#!/bin/sh
cap_case() {
printf "Capitalize: "
echo "$*" | sed -e 'y/-/_/' -e 's/\(^\|_\)[[:alpha:]]/\U&/g'
}
echo $(cap_case "snake_case")
Note that the \u / \U replacement is a GNU extension to sed - if you're using a non-GNU implementation, check whether it supports this feature.
For every time the pattern shows up (In this example the case of a 2 digit number) I want to pass that pattern to a script and replace that pattern with the output of a script.
I'm using sed an example of what it should look like would be
echo 'siedi87sik65owk55dkd' | sed 's/[0-9][0-9]/.\/script.sh/g'
Right now this returns
siedi./script.shsik./script.showk./script.shdkd
But I would like it to return
siedi!!!87!!!sik!!!65!!!owk!!!55!!!dkd
This is what is in ./script.sh
#!/bin/bash
echo "!!!$1!!!"
It has to be replaced with the output. In this example I know I could just use a normal sed substitution but I don't want that as an answer.
sed is for simple substitutions on individual lines, that is all. Anything else, even if it can be done, requires arcane language constructs that became obsolete in the mid-1970s when awk was invented and are used today purely for the mental exercise. Your problem is not a simple substitution so you shouldn't try to use sed to solve it.
You're going to want something like:
awk '{
head = ""
tail = $0
while ( match(tail,/[0-9]{2}/) ) {
tgt = substr(tail,RSTART,RLENGTH)
cmd = "./script.sh " tgt
if ( (cmd | getline line) > 0) {
tgt = line
}
close(cmd)
head = head substr(tail,1,RSTART-1) tgt
tail = substr(tail,RSTART+RLENGTH)
}
print head tail
}'
e.g. using an echo in place of your script.sh command:
$ echo 'siedi87sik65owk55dkd' |
awk '{
head = ""
tail = $0
while ( match(tail,/[0-9]{2}/) ) {
tgt = substr(tail,RSTART,RLENGTH)
cmd = "echo !!!" tgt "!!!"
if ( (cmd | getline line) > 0) {
tgt = line
}
close(cmd)
head = head substr(tail,1,RSTART-1) tgt
tail = substr(tail,RSTART+RLENGTH)
}
print head tail
}'
siedi!!!87!!!sik!!!65!!!owk!!!55!!!dkd
Ed's awk solution is obviously the way to go here.
For fun, I tried to come up with a sed solution, and here is (a convoluted GNU sed) one that takes the pattern and the script to be run as parameters; the input is either read from standard input (i.e., you can pipe to it) or from a file supplied as the third argument.
For your example, we'd have infile with contents
siedi87sik65owk55dkd
siedi11sik22owk33dkd
(two lines to demonstrate how this works for multiple lines), then script with contents
#!/bin/bash
echo "!!!${1}!!!"
and finally the solution script itself, so. Usage is
./so pattern script [input]
where pattern is an extended regular expression as understood by GNU sed (with the -r option), script is the name of the command you want to run for each match, and the optional input is the name of the input file if input is not standard input.
For your example, this would be
./so '[[:digit:]]{2}' script infile
or, as a filter,
cat infile | ./so '[[:digit:]]{2}' script
with output
siedi!!!87!!!sik!!!65!!!owk!!!55!!!dkd
siedi!!!11!!!sik!!!22!!!owk!!!33!!!dkd
This is what so looks like:
#!/bin/bash
pat=$1 # The pattern to match
script=$2 # The command to run for each pattern
infile=${3:-/dev/stdin} # Read from standard input if not supplied
# Use sed and have $pattern and $script expand to the supplied parameters
sed -r "
:build_loop # Label to loop back to
h # Copy pattern space to hold space
s/.*($pat).*/.\/\"$script\" \1/ # (1) Extract last match and prepare command
# Replace pattern space with output of command
e
G # (2) Append hold space to pattern space
s/(.*)$pat(.*)/\1~~~\2/ # (3) Replace last match of pattern with ~~~
/\n[^\n]*$pat[^\n]*$/b build_loop # Loop if string contains match
:fill_loop # Label for second loop
s/(.*\n)(.*)\n([^\n]*)~~~([^\n]*)$/\1\3\2\4/ # (4) Replace last ~~~
t fill_loop # Loop if there was a replacement
s/(.*)\n(.*)~~~(.*)$/\2\1\3/ # (5) Final ~~~ replacement
" < "$infile"
The sed command works with two loops. The first one copies the pattern space to the hold space, then removes everything but the last match from the pattern space and prepares the command to be run. After the substitution with (1) in its comment, the pattern space looks like this:
./script 55
The e command (a GNU extension) then replaces the pattern space with the output of this command. After this, G appends the hold space to the pattern space (2). The pattern space now looks like this:
!!!55!!!
siedi87sik65owk55dkd
The substitution at (3) replaces the last match with a string hopefully not equal to the pattern and we get
!!!55!!!
siedi87sik65owk~~~dkd
The loop repeats if the last line of the pattern space still has a match for the pattern. After three loops, the pattern space looks like this:
!!!87!!!
!!!65!!!
!!!55!!!
siedi~~~sik~~~owk~~~dkd
The second loop now replaces the last ~~~ with the second to last line of the pattern space with substitution (4). The command uses lots of "not a newline" ([^\n]) to make sure we're not pulling the wrong replacement for ~~~.
Because of the way command (4) is written, the loop ends with one last substitution to go, so before command (5), we have this pattern space:
!!!87!!!
siedi~~~sik!!!65!!!owk!!!55!!!dkd
Command (5) is a simpler version of command (4), and after it, the output is as desired.
This seems to be fairly robust and can deal with spaces in the name of the script to be run as long as it's properly quoted when calling:
./so '[[:digit:]]{2}' 'my script' infile
This would fail if
The input file contains ~~~ (solvable by replacing all occurrences at the start, putting them back at the end)
The output of script contains ~~~
The pattern contains ~~~
i.e., the solution very much depends on ~~~ being unique.
Because nobody asked: so as a one-liner.
#!/bin/bash
sed -re ":b;h;s/.*($1).*/.\/\"$2\" \1/;e" -e "G;s/(.*)$1(.*)/\1~~~\2/;/\n[^\n]*$1[^\n]*$/bb;:f;s/(.*\n)(.*)\n([^\n]*)~~~([^\n]*)$/\1\3\2\4/;tf;s/(.*)\n(.*)~~~(.*)$/\2\1\3/" < "${3:-/dev/stdin}"
Still works!
A conceptually simpler multi-utility solution:
Using GNU utilities:
echo 'siedi87sik65owk55dkd' |
sed 's|[0-9]\{2\}|$(./script.sh &)|g' |
xargs -d'\n' -I% sh -c 'echo '\"%\"
Using BSD utilities (also works with GNU utilities):
echo 'siedi87sik65owk55dkd' |
sed 's|[0-9]\{2\}|$(./script.sh &)|g' | tr '\n' '\0' |
xargs -0 -I% sh -c 'echo '\"%\"
The idea is to use sed to translate the tokens of interest lexically into a string containing shell command substitutions that invoke the target script with the token, and then pass the result to the shell for evaluation.
Note:
Any embedded " and $ characters in the input must be \-escaped.
xargs -d'\n' (GNU) and tr '\n' '\0' / xargs -0 (BSD) are only needed to correctly preserve whitespace in the input - if that is not needed, the following POSIX-compliant solution will do:
echo 'siedi87sik65owk55dkd' |
sed 's|[0-9]\{2\}|$(./script.sh &)|g' | tr '\n' '\0' |
xargs -I% sh -c 'printf "%s\n" '\"%\"
I have multiple .txt files, in which I want to replace the strings
old -> new
Old -> New
OLD -> NEW
The first step is to only replace one string Old->New. Here is my current code, but it does not do the job (the files remain unchanged). The sed line works only if I replace the variables with the actual strings.
#!/bin/bash
old_string="Old"
new_string="New"
sed -i '.bak' 's/$old_string/$new_string/g' *.txt
Also, how do I convert a string to all upper-caps and all lower-caps?
Thank you very much for your advice!
To complement #merlin2011's helpful answer:
If you wanted to create the case variants dynamically, try this:
# Define search and replacement strings
# as all-lowercase.
old_string='old'
new_string='new'
# Loop 3 times and create the case variants dynamically.
# Build up a _single_ sed command that performs all 3
# replacements.
sedCmd=
for (( i = 1; i <= 3; i++ )); do
case $i in
1) # as defined (all-lowercase)
old_string_variant=$old_string
new_string_variant=$new_string
;;
2) # initial capital
old_string_variant="$(tr '[:lower:]' '[:upper:]' <<<"${old_string:0:1}")${old_string:1}"
new_string_variant="$(tr '[:lower:]' '[:upper:]' <<<"${new_string:0:1}")${new_string:1}"
;;
3) # all-uppercase
old_string_variant=$(tr '[:lower:]' '[:upper:]' <<<"$old_string")
new_string_variant=$(tr '[:lower:]' '[:upper:]' <<<"$new_string")
;;
esac
# Append to the sed command string. Note the use of _double_ quotes
# to ensure that variable references are expanded.
sedCmd+="s/$old_string_variant/$new_string_variant/g; "
done
# Finally, invoke sed.
sed -i '.bak' "$sedCmd" *.txt
Note that bash 4 supports case conversions directly (as part of parameter expansion), but OS X, as of 10.9.3, is still on bash 3.2.51.
Alternative solution, using awk to create the case variants and synthesize the sed command:
Aside from being shorter, it is also more robust, because it also handles strings correctly that happen to contain characters that are regex metacharacters (characters with special meaning in an regular expression, e.g., *) or have special meaning in sed's s function's replacement-string parameter (e.g., \), through appropriate escaping; without escaping, the sed command would not work as expected.
Caveat: Doesn't support strings with embedded \n chars. (though that could be fixed, too).
# Define search and replacement strings as all-lowercase literals.
old_string='old'
new_string='new'
# Synthesize the sed command string, utilizing awk and its tolower() and toupper()
# functions to create the case variants.
# Note the need to escape \ chars to prevent awk from interpreting them.
sedCmd=$(awk \
-v old_string="${old_string//\\/\\\\}" \
-v new_string="${new_string//\\/\\\\}" \
'BEGIN {
printf "s/%s/%s/g; s/%s/%s/g; s/%s/%s/g",
old_string, new_string,
toupper(substr(old_string,1,1)) substr(old_string,2), toupper(substr(new_string,1,1)) substr(new_string,2),
toupper(old_string), toupper(new_string)
}')
# Invoke sed with the synthesized command.
# The inner sed command ensures that all regex metacharacters in the strings
# are escaped so that sed treats them as literals.
sed -i '.bak' "$(sed 's#[][(){}^$.*?+\]#\\&#g' <<<"$sedCmd")" *.txt
If you want to do bash variable expansion inside the argument to sed, you need to use double quotes " instead of single quotes '.
sed -i '.bak' "s/$old_string/$new_string/g" *.txt
In terms of getting matches on all three of the literal substitutions, the cleanest solution may be just to run sed three times in a loop like this.
declare -a olds=(old Old OLD)
declare -a news=(new New NEW)
for i in `seq 0 2`; do
sed -i "s/${olds[$i]}/${news[$i]}/g" *.txt
done;
Update: The solution above works on Linux, but apparently OS X has different requirements. Additionally, as #mklement0 mentioned, my for loop is silly. Here is an improved version for OS X.
declare -a olds=(old Old OLD)
declare -a news=(new New NEW)
for (( i = 0; i < ${#olds[#]}; i++ )); do
sed -i '.bak' "s/${olds[$i]}/${news[$i]}/g" *.txt
done;
Assuming each string is separated by spaces from your other strings and that you don't want partial matches within longer strings and that you don't care about preserving white space on output and assuming that if an "old" string matches on a "new" string after a previous conversion operation, then the string should be changed again:
$ cat tst.awk
BEGIN {
split(tolower(old),oldStrs)
split(tolower(new),newStrs)
}
{
for (fldNr=1; fldNr<=NF; fldNr++) {
for (stringNr=1; stringNr in oldStrs; stringNr++) {
oldStr = oldStrs[stringNr]
if (tolower($fldNr) == oldStr) {
newStr = newStrs[stringNr]
split(newStr,newChars,"")
split($fldNr,fldChars,"")
$fldNr = ""
for (charNr=1; charNr in fldChars; charNr++) {
fldChar = fldChars[charNr]
newChar = newChars[charNr]
$fldNr = $fldNr ( fldChar ~ /[[:lower:]]/ ?
newChar : toupper(newChar) )
}
}
}
}
print
}
.
$ cat file
The old Old OLD smOLDering QuICk brown FoX jumped
$ awk -v old="old" -v new="new" -f tst.awk file
The new New NEW smOLDering QuICk brown FoX jumped
Note that the "old" in "smOLDering" did not get changed. Is that desirable?
$ awk -v old="QUIck Fox" -v new="raBid DOG" -f tst.awk file
The old Old OLD smOLDering RaBId brown DoG jumped
$ awk -v old="THE brown Jumped" -v new="FEW dingy TuRnEd" -f tst.awk file
Few old Old OLD smOLDering QuICk dingy FoX turned
Think about whether or not this is your expected output:
$ awk -v old="old new" -v new="new yes" -f tst.awk file
The yes Yes YES smOLDering QuICk brown FoX jumped
A few lines of sample input and expected output in the question would be useful to avoid all the guessing and assumptions.