replace file path name from multiple file using sed - bash

I want to replace <lexicon uri="file://C:/image/png/grammars/custom/image-custom.lex?SWI.type=backup"/><lexicon uri="file://C:/image/jpg/grammars/custom/image-dot-custom.lex?SWI.type=backup"/> with null in multiple files.
The code is given below.
sed -i s|<lexicon uri="file://C:/image/png/grammars/custom/image-custom.lex?SWI.type=backup"/><lexicon uri="file://C:/image/jpg/grammars/custom/image-dot-custom.lex?SWI.type=backup"/>||g *
Here I am getting this error:
< was unexpected at this time.
Please clarify for me what is not working here.

Could you please try following and let me know if this helps you. By using # as sed's separator you need not to escape / in it only need to escape ., ? not to take their special meaning
sed -E 's#<lexicon uri="file://C:/image/png/grammars/custom/image-custom\.lex\?SWI\.type=backup"/><lexicon uri="file://C:/image/jpg/grammars/custom/image-dot-custom\.lex\?SWI\.type=backup"/>##' Input_file
Tested it with:
sed --version
GNU sed version 4.2.1

works with #
sed -i -e 's#<lexicon uri="file://C:/image/png/grammars/custom/image-custom.lex?SWI.type=backup"/><lexicon uri="file://C:/image/jpg/grammars/custom/image-dot-custom.lex?SWI.type=backup"/>##g' test.txt

The pattern contains shell metacharacters, which need to be quoted or escaped. Usually, in Bash, you should use single quotes around strings, unless you need the shell to interpolate variables and command substitutions and interpret backslash sequences (in which case use double quotes) or to also perform whitespace tokenization and wildcard expansion (in which case use no quotes). See also When to wrap quotes around a shell variable?
sed -i 's|<lexicon uri="file://C:/image/png/grammars/custom/image-custom.lex?SWI.type=backup"/><lexicon uri="file://C:/image/jpg/grammars/custom/image-dot-custom.lex?SWI.type=backup"/>||' *
I also took out the g flag, which only makes sense if you expect multiple matches within a single line. (Perhaps you do after all, in which case obviously put it back.)

Related

replace entire line in file with new line given arguments line number and replacement string with special characters

I have 2 bash script variables defined:
THELINENUMBER="14" # an arbitrary line number, comes from a separate command
NEWLINE="a line/ with# special! characters<" # arbitrary line with special characters, comes from separate command
I need to use the line number ${THELINENUMBER} to replace a line in a file called after.txt with ${NEWLINE}.
How do I do that?
These are some examples I have tried:
sed -i '${THELINENUMBER}s#.*#"/"${NEWLINE}"/"' after.txt
sed -i "${THELINENUMBER}s#.*#"/"${NEWLINE}"/"" after.txt
sed -i "${THELINENUMBER}s/.*/'${NEWLINE}'" after.txt
sed -i '${THELINENUMBER}s,.*,${NEWLINE}' after.txt
I am told that the delimitter is usually a /, but those are present in my line replacement variable, so I can't use those. I tried with # and , but the desired behavior did not change. I am also told that " and ' are supposed to be used to turn off escaping in text (use literal string), but I have not been able to get that to work either. How do I pass in a string parameter into sed that has special characters? I am wondering if I should pass the variable ${NEWLINE} into another built-in function call to add escape characters or something before passing it into sed. Is sed the right tool for the job? I did not find much helpful information looking at the CLI manpages. I use Ubuntu 18.04.
I have referred to these sources in my internet search:
https://stackoverflow.com/questions/11145270/how-to-replace-an-entire-line-in-a-text-file-by-line-number
https://askubuntu.com/questions/76808/how-do-i-use-variables-in-a-sed-command
https://stackoverflow.com/questions/37372047/find-a-line-with-a-string-and-replace-entire-line-with-another-line
Use the c (change) command.
By the way, the naming convention for regular shell variables is NOT ALLCAPS, as that may result in accidental collisions with special variables like PATH.
sed "$linenumber c\\
$newline" file
Try
sed -i "${THELINENUMBER}s#.*#${NEWLINE}#" after.txt
this works because:
You require " enclosing the entire sed command instead of backtick so that the variables are expanded
No other quotes or backticks are needed to escape " in the variables as there aren't any: there are no literal (escaped) quotes inside the variables
An alternate separator (such as #) is required due to the / inside the NEWLINE variable.

sed complains on numbers in bash script

I'm writing a script to replace dafault configuration values to user specified ones. But i'm getting unterminated 's' command errors from sed. After 2 Hours of googling i still haven't figured out whats causing this. The lines are:
CONFIG_GMETAD_COMPUTENODES="scccompute1 scccompute2"
CONFIG_GMETAD="/etc/gmetad.conf"
sed -i 's/localhost/'${CONFIG_GMETAD_COMPUTENODES}'/g' ${CONFIG_GMETAD}
this substitutes to
sed -i 's/localhost/scccompute1 scccompute2/g' /etc/gmetad.conf
error i get
sed: -e expression #1, char 23: unterminated `s' command
I don't see whats wrong in here, but haven't worked quite often with sed.
You need to quote your variables. Note how the sed command expands:
sed -i 's/localhost/'scccompute1 scccompute2'/g' /etc/gmetad.conf
This creates multiple options, not a single one with your sed script. Instead, try:
sed -i 's/localhost/'"${CONFIG_GMETAD_COMPUTENODES}"'/g' "${CONFIG_GMETAD}"
Containing the variable within double quotes causes the whole string to be treated as a single argument to sed, which is what you want. And of course, quotes around the filename because the filename might contain special characters. As a rule, always quote variables when you refer to them in bash.
Note that if the embedded variable contains slashes or some other special characters, it may break your script. So you might want to do some sanity checking before feeding it to sed:
CONFIG_GMETAD_COMPUTENODES="${CONFIG_GMETAD_COMPUTENODES//[^a-z0-9 ]/}"
This will strip all characters that are not alphanumeric or space, if bash is your shell.
The problem come from quoting in bash.
You should use
sed -i "s/localhost/${CONFIG_GMETAD_COMPUTENODES}/g"

How to use bash variables in sed command?

I want to do (in bash script):
NEWBASE=`echo $NAME | sed "s/${DIR}//g" | sed 's/.\///g'`
I read in the net, that I have to replace single quote with double quote.
This is unfortunately not working. Why? Thanks
sed is overkill for this. Use parameter expansion:
NEWBASE=${NAME//$DIR//}
NEWBASE=${NEWBASE//.\//}
It is important to understand that bash and sed are two completely independent things. When you give bash a command, it first processes it according to its rules, in order to come up with a utility name and a set of arguments for that utility (in this case sed), and then calls the utility with the arguments.
Probably $DIR contains a slash character. Perhaps it looks something like /usr/home/codyline/src.
So when bash substitutes that into the argument to the sed command:
"s/${DIR}//g"
the result is
s//usr/home/codyline/src//g
which is what is then passed to sed. But sed can't understand that commabnd: it has (many) too many / characters.
If you really want to use sed for this purpose, you need to use a delimiter other than /, and it needs to be a character you are confident will never appear in $DIR. Fortunately, the sed s command allows you to use any character as a delimiter: whatever character follows the s is used as the delimiter. But there always must be exactly three of them in the command.
For example, you might believe that no directory path contains a colon (:), in which case you could use:
sed "s:${DIR}::g"
Of course, someday that will fail precisely because you have a directory with a colon in its name. So you could make things more general by using bash's substitute-and-replace feature to backslash-escape all the colons:
sed "s:${DIR//:/\:}::g"
But you could have used this bash feature in order to avoid the use of sed altogether:
NEWBASE=${NAME//$DIR}
Unfortunately, you can't nest bash substitute-and-replaces, so you need to do them sequentially:
NEWBASE=${NEWBASE//.\/}
Note: I used ${var//...}, which is the equivalent of specifying the g flag in a sed s command, but I really don't know if it is appropriate. Do you really expect multiple instances of $DIR in a single path? If there are multiple instances, do you really want to remove all of them? You'll have to decide.

using sed substitute with a bash variable

I'm trying to:
sed -i s/installpath/"$INSTALL_PATH"/ /tmp/myscript.conf
when $INSTALL_PATH is just a string everything works. but if install path is an actual path (II guess the '/' char is the problem) like /home/ubuntu/install_script. then It breaks with the following error message:
sed: -e expression #1, char 16: unknown option to `s'
btw: I tried without the "" around $INSTALL_PATH. didn't work
Thanks for the help!
It is likely that $INSTALL_PATH contains slashes, which means that they will be interpreted by sed as part of the s/pattern/replacement/ construct. To avoid this, you should use a different separator, for example ~:
sed -i "s~installpath~$INSTALL_PATH~" /tmp/myscript.conf
I have also wrapped the whole sed line in quotes rather than quoting one section. In general, it's a good idea to do this as it prevents other characters from being interpreted by the shell. Normally single quotes are used but if shell variables are to be expanded, use double quotes.
You don't have to use / as the delimiter in sed commands. Use something that's less likely to occur in a filename, e.g.:
sed -i s^installpath^"$INSTALL_PATH"^ /tmp/myscript.conf
If you're careful with quoting you can use other characters which are even less likely to exist inside a filename:
sed -i "s|installpath|$INSTALL_PATH|" /tmp/myscript.conf
The pipe is outright illegal in Windows paths, and on Linux it's a really bad idea and unlikely to occur in the wild.

replace substring in lines using sed or grep

I have a file with a lot of lines, two of them are:
videoId: 'S2Rgr6yuuXQ'
var vid_seq=1;
in a shell script, I have two variables,
for id, the value is always 11 characters/numbers
id='fsafsferii2'
id_seq=80
I want to modify these two lines with id and id_seq
videoId: 'fsafsferii2'
var vid_seq=80;
I used
sed -i 's/\(videoId: \).*\\1'${id}'/\2' file
but there are errors, what is wrong with my script?
thanks
The grep command won't "replace" text, it is for "global regular expression print". But sed will.
sed -i'' '/^videoId: /s/: .*/: '"$id"'/;/^var vid_seq=/s/=.*/='"$id_seq"';/'
I'm not a big fan of inserting variables into sed scripts this way, but sed is simple, and provides no mechanism for actually using actual variables on its own. If you're going to do this, include some format checking for the two variables to make sure they contain the data you want them to contain, before you run this sed script. An accidental / in a variable would cause the sed script to fail.
UPDATE per comments:
Here's a successful test:
$ id=fsafsferii2
$ id_seq=80
$ cat inp686
videoId: 'S2Rgr6yuuXQ'
var vid_seq=1;
$ sed '/^videoId: /s/: .*/: '"$id"'/;/^var vid_seq=/s/=.*/='"$id_seq"';/' < inp686
videoId: fsafsferii2
var vid_seq=80;
$
Of course, you'll need to do some quote magic to get the single quotes into your videoId, but I'm sure you can figure that out yourself.
UPDATE 2
According to sed's man page, the substitute command is in the form:
[2addr]s/regular expression/replacement/flags
The [2addr] means you can specify up to two "addresses", which can be line numbers or regular expressions to match. So the s (substitute) command can take a line, a range, a match, or a span between matches. In our case, we're just using a single match to identify what lines we want to execute the substitution on.
The script above is made up of two sed commands, separated by a semicolon.
/^videoId: / -- Match lines that start with the word videoId:...
s/: .*/: '"$id"'/; -- Substitute all text from the colon to the end of the line with whatever is in the $id environment variable.
/^var vid_seq=/ -- Match lines that ... meh, as above.
s/=.*/='"$id_seq"';/ -- Substitute all text from the equals sign on with $id_seq.
Note that the '"$id"' construct means that we are exiting the single quotes, then immediately entering double quotes for the expansion of the variable ... then exiting the double quotes and going back into a new set of single quotes. Sed scripts are safest inside single quotes because of the frequent use of characters that might be interpreted by a shell.
Note also that because sed's substitute command uses a forward slash as a delimiter, the $id and $id_seq variables may not contain a slash. If they might, you can switch to a different delimiter.
What is wrong with:
sed -i 's/\(videoId: \).*\\1'${id}'/\2' file
Missing the third delimiter (/). Valid syntax is s/regex/replace/
Incorrect regex pattern (let's assume ${id} has been substituted)
\(videoId: \).*\\1fsafsferii2
is telling it to match a string that looks like this:
videoId: anything\1fsafsferii2
(\\ in regex matches literal backslash, so \\1 would match a literal backslash followed by 1 instead of 1st sub-expression)
Replace the matched string with \2
But since there is only one set of parentheses, \2 is actually empty.
Also, since the regex pattern in 2. doesn't match anything, nothing is replaced.
This should work (GNU sed)
sed -i 's/\(videoId: \).*/\1 \x27'${id}'\x27/
s/\(var vid_seq=\).*/\1'${id_seq}'\;/' file
Note:
\x27 is the hexadecimal representation of single quote (to prevent clashing with the other single quote)
\; for literal semicolon. If ; is not escaped, it's interpreted to terminate the s command in sed.

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