I have redirected some string into one parameter for ex: ab=jyoti,priya, pranit
I have one file : Name.txt which contains -
jyoti
prathmesh
John
Kelvin
pranit
I want to delete the records from the Name.txt file which are contain in ab parameter.
Please suggest if this can be done ?
If ab is a shell variable, you can easily turn it into an extended regular expression, and use it with grep -E:
grep -E -x -v "${ab//,/|}" Name.txt
The string substitution ${ab//,/|} returns the value of $ab with every , substituted with a | which turns it into an extended regular expression, suitable for passing as an argument to grep -E.
The -v option says to remove matching lines.
The -x option specifies that the match needs to cover the whole input line, so that a short substring will not cause an entire longer line to be removed. Without it, ab=prat would cause pratmesh to be removed.
If you really require a sed solution, the transformation should be fairly trivial. grep -E -v -x 'aaa|bbb|ccc' is equivalent to sed '/^\(aaa\|bbb\|ccc)$/d' (with some dialects disliking the backslashes, and others requiring them).
To do an in-place edit (modify Name.txt without a temporary file), try this:
sed -i "/^\(${ab//,/\|}\)\$/d" Name.txt
This is not entirely robust against strings containing whitespace or other shell metacharacters, but if you just need
Try with
sed -e 's/\bjyoti\b//g;s/\bpriya\b//g' < Name.txt
(using \b assuming you need word boundaries)
this will do it:
for param in `echo $ab | sed -e 's/[ ]+//g' -e 's/,/ /g'` ; do res=`sed -e "s/$param//g" < name.txt`; echo $res > name.txt; done
echo $res
Related
If I run these commands from a script:
#my.sh
PWD=bla
sed 's/xxx/'$PWD'/'
...
$ ./my.sh
xxx
bla
it is fine.
But, if I run:
#my.sh
sed 's/xxx/'$PWD'/'
...
$ ./my.sh
$ sed: -e expression #1, char 8: Unknown option to `s'
I read in tutorials that to substitute environment variables from shell you need to stop, and 'out quote' the $varname part so that it is not substituted directly, which is what I did, and which works only if the variable is defined immediately before.
How can I get sed to recognize a $var as an environment variable as it is defined in the shell?
Your two examples look identical, which makes problems hard to diagnose. Potential problems:
You may need double quotes, as in sed 's/xxx/'"$PWD"'/'
$PWD may contain a slash, in which case you need to find a character not contained in $PWD to use as a delimiter.
To nail both issues at once, perhaps
sed 's#xxx#'"$PWD"'#'
In addition to Norman Ramsey's answer, I'd like to add that you can double-quote the entire string (which may make the statement more readable and less error prone).
So if you want to search for 'foo' and replace it with the content of $BAR, you can enclose the sed command in double-quotes.
sed 's/foo/$BAR/g'
sed "s/foo/$BAR/g"
In the first, $BAR will not expand correctly while in the second $BAR will expand correctly.
Another easy alternative:
Since $PWD will usually contain a slash /, use | instead of / for the sed statement:
sed -e "s|xxx|$PWD|"
You can use other characters besides "/" in substitution:
sed "s#$1#$2#g" -i FILE
一. bad way: change delimiter
sed 's/xxx/'"$PWD"'/'
sed 's:xxx:'"$PWD"':'
sed 's#xxx#'"$PWD"'#'
maybe those not the final answer,
you can not known what character will occur in $PWD, / : OR #.
if delimiter char in $PWD, they will break the expression
the good way is replace(escape) the special character in $PWD.
二. good way: escape delimiter
for example:
try to replace URL as $url (has : / in content)
x.com:80/aa/bb/aa.js
in string $tmp
URL
A. use / as delimiter
escape / as \/ in var (before use in sed expression)
## step 1: try escape
echo ${url//\//\\/}
x.com:80\/aa\/bb\/aa.js #escape fine
echo ${url//\//\/}
x.com:80/aa/bb/aa.js #escape not success
echo "${url//\//\/}"
x.com:80\/aa\/bb\/aa.js #escape fine, notice `"`
## step 2: do sed
echo $tmp | sed "s/URL/${url//\//\\/}/"
URL
echo $tmp | sed "s/URL/${url//\//\/}/"
URL
OR
B. use : as delimiter (more readable than /)
escape : as \: in var (before use in sed expression)
## step 1: try escape
echo ${url//:/\:}
x.com:80/aa/bb/aa.js #escape not success
echo "${url//:/\:}"
x.com\:80/aa/bb/aa.js #escape fine, notice `"`
## step 2: do sed
echo $tmp | sed "s:URL:${url//:/\:}:g"
x.com:80/aa/bb/aa.js
With your question edit, I see your problem. Let's say the current directory is /home/yourname ... in this case, your command below:
sed 's/xxx/'$PWD'/'
will be expanded to
sed `s/xxx//home/yourname//
which is not valid. You need to put a \ character in front of each / in your $PWD if you want to do this.
Actually, the simplest thing (in GNU sed, at least) is to use a different separator for the sed substitution (s) command. So, instead of s/pattern/'$mypath'/ being expanded to s/pattern//my/path/, which will of course confuse the s command, use s!pattern!'$mypath'!, which will be expanded to s!pattern!/my/path!. I’ve used the bang (!) character (or use anything you like) which avoids the usual, but-by-no-means-your-only-choice forward slash as the separator.
Dealing with VARIABLES within sed
[root#gislab00207 ldom]# echo domainname: None > /tmp/1.txt
[root#gislab00207 ldom]# cat /tmp/1.txt
domainname: None
[root#gislab00207 ldom]# echo ${DOMAIN_NAME}
dcsw-79-98vm.us.oracle.com
[root#gislab00207 ldom]# cat /tmp/1.txt | sed -e 's/domainname: None/domainname: ${DOMAIN_NAME}/g'
--- Below is the result -- very funny.
domainname: ${DOMAIN_NAME}
--- You need to single quote your variable like this ...
[root#gislab00207 ldom]# cat /tmp/1.txt | sed -e 's/domainname: None/domainname: '${DOMAIN_NAME}'/g'
--- The right result is below
domainname: dcsw-79-98vm.us.oracle.com
VAR=8675309
echo "abcde:jhdfj$jhbsfiy/.hghi$jh:12345:dgve::" |\
sed 's/:[0-9]*:/:'$VAR':/1'
where VAR contains what you want to replace the field with
I had similar problem, I had a list and I have to build a SQL script based on template (that contained #INPUT# as element to replace):
for i in LIST
do
awk "sub(/\#INPUT\#/,\"${i}\");" template.sql >> output
done
If your replacement string may contain other sed control characters, then a two-step substitution (first escaping the replacement string) may be what you want:
PWD='/a\1&b$_' # these are problematic for sed
PWD_ESC=$(printf '%s\n' "$PWD" | sed -e 's/[\/&]/\\&/g')
echo 'xxx' | sed "s/xxx/$PWD_ESC/" # now this works as expected
for me to replace some text against the value of an environment variable in a file with sed works only with quota as the following:
sed -i 's/original_value/'"$MY_ENVIRNONMENT_VARIABLE"'/g' myfile.txt
BUT when the value of MY_ENVIRONMENT_VARIABLE contains a URL (ie https://andreas.gr) then the above was not working.
THEN use different delimiter:
sed -i "s|original_value|$MY_ENVIRNONMENT_VARIABLE|g" myfile.txt
I'm using sed to replace values in other bash scripts, such as:
somedata="$(<somefile.sh)"
somedata=`sed 's/ ==/==/g' <<< $somedata` # [space]== becomes ==
somedata=`sed 's/== /==/g' <<< $somedata` # ==[space] becomes ==
The same for ||, &&, !=, etc. I think steps should be reduced with the right regex match. The operator does not need surrounding spaces, but may have a space before and after, only before, or only after. Is there a way to handle all of these with one sed command?
There are many other conditions not mentioned also. The script takes more time to execute than desired.
The goal is to reduce the overall execution time so I am hoping to reduce the number of commands used with clever regex to match multiple conditions.
I'm also considering tr, awk or perl - whichever is fastest?
With GNU sed, you can use the | (or) operator:
$ sed -r 's/ *(&&|\|\|) */\1/g' <<< "foo && bar || baz"
foo&&bar||baz
*(&&|\|\|) *: search for zero or more space followed by any of the | separated strings followed by zero or more space
the matching strings are captured and output using backreference
Edit:
As pointed out in comments, you can use the -E flag with GNU sed in place of -r. Your command will be more portable:
sed -E 's/ *(\&\&|\|\|) */\1/g'
As GNU sed also supports \| alternation operator with Basic Regular Expressions, you can use it for better readability:
sed 's/ *\(&&\|||\) */\1/g'
You can chain multiple sed substitutions with the -e flag:
$ echo -n "test data here" | sed -e 's/test/TEST/' \
-e 's/data/HERE/' \
-e 's/here/DATA/'
$ TEST HERE DATA
you can use a sedfile (-f option) alongside with the -i option (replace in-place, no need to store in env. variable):
sed -i -f mysedfile somefile.sh
mysedfile may contain expressions, 1 per line
s/ *&& */\&\&/g
s/ *== */==/g
(or use the -e option to use several expression, but if you have a lot of them, it wil become quickly unreadable)
BTW: -i option creates a temporary file within the processed file directory, so in the end, if operation succeeds, the original file is deleted and the temporary file is renamed into the original file name
When the end of the file is reached, the temporary file is renamed
to the output file's original name. The extension, if supplied,
is used to modify the name of the old file before renaming the
temporary file, thereby making a backup copy(2))
so there's no I/O overhead with that option. No need at all to store in a variable.
What I have:
test
more text
#user653434 text and so
test
more text
#user9659333 text and so
I'd like to filter this text and finally get the following list as .txt file:
user653434
user9659333
It's important to get the names without "#" sign.
Thx for help ;)
Using grep -P (requires GNU grep):
$ grep -oP '(?<=#)\w+' File
user653434
user9659333
-o tells grep to print only the match.
-P tells grep to use Perl-style regular expressions.
(?<=#) tells sed that # must precede the match but the # is not included in the match.
\w+ matches one or more word characters. This is what grep will print.
To change the file in place with grep:
grep -oP '(?<=#)\w+' File >tmp && mv tmp File
Using sed
$ sed -En 's/^#([[:alnum:]]+).*/\1/p' File
user653434
user9659333
And, to change the file in place:
sed -En -i.bak 's/^#([[:alnum:]]+).*/\1/p' File
-E tells sed to use the extended form of regular expressions. This reduces the need to use escapes.
-n tells sed not to print anything unless we explicitly ask it to.
-i.bak tells sed to change the file in place while leaving a backup file with the extension .bak.
The leading s in s/^#([[:alnum:]]+).*/\1/p tells sed that we are using a substitute command. The command has the typical form s/old/new/ where old is a regular expression and sed replaces old with new. The trailing p is an option to the substitute command: the p tells sed to print the resulting line.
In our case, the old part is ^#([[:alnum:]]+).*. Starting from the beginning of the line, ^, this matches # followed by one or more alphanumeric characters, ([[:alnum:]]+), followed by anything at all, .*. Because the alphanumeric characters are placed in parens, this is saved as a group, denoted \1.
The new part of the substitute command is just \1, the alphanumeric characters from above which comprise the user name.
Here, the s indicates that we are using a sed substitute command. The usual form
With GNU grep:
grep -Po '^#\K[^ ]*' file
Output:
user653434
user9659333
See: The Stack Overflow Regular Expressions FAQ
Using bash, how would one replace all unquoted characters from a file?
I have a system that I can't modify that spits out CSV files such as:
code;prop1;prop2;prop3;prop4;prop5;prop6
0,1000,89,"a1,a2,a3",33,,
1,,,"a55,a10",1,1 L,87
2,25,1001,a4,,"1,5 L",
I need this to become, for a new system being added
code;prop1;prop2;prop3;prop4;prop5;prop6
0;1000;89;a1,a2,a3;33;;
1;;;a55,a10;1;1 L;87
2;25;1001;a4;1,5 L;
If the quotes can be removed after this substitution happens in one command it would be nice :) But I prefer clarity to complicated one-liners for future maintenance.
Thank you
With sed:
sed -e 's/,/;/g' -e ':loop; s/\("\)\([^;]*\);\([^"]*"\)/\1\2,\3/; t loop'
Test:
$ sed -e 's/,/;/g' -e ':loop; s/\("\)\([^;]*\);\([^"]*"\)/\1\2,\3/; t loop' yourfile
code;prop1;prop2;prop3;prop4;prop5;prop6
0;1000;89;"a1,a2,a3";33;;
1;;;"a55,a10";1;1 L;87
2;25;1001;a4;;"1,5 L";
You want to use a csv parser. Parsing csv with shell tools is hard (you will encounter regular expressions soon, and they rarely get all cases).
There is one in almost every language. I recommend python.
You can also do this using excel/openoffice variants by opening the file and then saving with ; as the separator.
You can used sed:
echo '0,1000,89,"a1,a2,a3",33,,' | sed -e "s|\"||g"
This will replace " with the empty string (deletes it), and you can pipe another sed to replace the , with ;:
sed -e "s|,|;|g"
$ echo '0,1000,89,"a1,a2,a3",33,,' | sed -e "s|\"||g" | sed -e "s|,|;|g"
>> 0;1000;89;a1;a2;a3;33;;
Note that you can use any separator you want instead of | inside the sed command. For example, you can rewrite the first sed as:
sed -e "s-\"--g"
I have a large number of words in a text file to replace.
This script is working up until the sed command where I get:
sed: 1: "*.js": invalid command code *
PS... Bash isn't one of my strong points - this doesn't need to be pretty or efficient
cd '/Users/xxxxxx/Sites/xxxxxx'
echo `pwd`;
for line in `cat myFile.txt`
do
export IFS=":"
i=0
list=()
for word in $line; do
list[$i]=$word
i=$[i+1]
done
echo ${list[0]}
echo ${list[1]}
sed -i "s/{$list[0]}/{$list[1]}/g" *.js
done
You're running BSD sed (under OS X), therefore the -i flag requires an argument specifying what you want the suffix to be.
Also, no files match the glob *.js.
This looks like a simple typo:
sed -i "s/{$list[0]}/{$list[1]}/g" *.js
Should be:
sed -i "s/${list[0]}/${list[1]}/g" *.js
(just like the echo lines above)
So myFile.txt contains a list of from:to substitutions, and you are looping over each of those. Why don't you create a sed script from this file instead?
cd '/Users/xxxxxx/Sites/xxxxxx'
sed -e 's/^/s:/' -e 's/$/:/' myFile.txt |
# Output from first sed script is a sed script!
# It contains substitutions like this:
# s:from:to:
# s:other:substitute:
sed -f - -i~ *.js
Your sed might not like the -f - which means sed should read its script from standard input. If that is the case, perhaps you can create a temporary script like this instead;
sed -e 's/^/s:/' -e 's/$/:/' myFile.txt >script.sed
sed -f script.sed -i~ *.js
Another approach, if you don't feel very confident with sed and think you are going to forget in a week what the meaning of that voodoo symbols is, could be using IFS in a more efficient way:
IFS=":"
cat myFile.txt | while read PATTERN REPLACEMENT # You feed the while loop with stdout lines and read fields separated by ":"
do
sed -i "s/${PATTERN}/${REPLACEMENT}/g"
done
The only pitfall I can see (it may be more) is that if whether PATTERN or REPLACEMENT contain a slash (/) they are going to destroy your sed expression.
You can change the sed separator with a non-printable character and you should be safe.
Anyway, if you know whats on your myFile.txt you can just use any.