Is there an invocation of sed todo in-place editing without backups that works both on Linux and Mac? While the BSD sed shipped with OS X seems to need sed -i '' …, the GNU sed Linux distributions usually come with interprets the quotes as empty input file name (instead of the backup extension), and needs sed -i … instead.
Is there any command line syntax which works with both flavors, so I can use the same script on both systems?
If you really want to just use sed -i the 'easy' way, the following DOES work on both GNU and BSD/Mac sed:
sed -i.bak 's/foo/bar/' filename
Note the lack of space and the dot.
Proof:
# GNU sed
% sed --version | head -1
GNU sed version 4.2.1
% echo 'foo' > file
% sed -i.bak 's/foo/bar/' ./file
% ls
file file.bak
% cat ./file
bar
# BSD sed
% sed --version 2>&1 | head -1
sed: illegal option -- -
% echo 'foo' > file
% sed -i.bak 's/foo/bar/' ./file
% ls
file file.bak
% cat ./file
bar
Obviously you could then just delete the .bak files.
This works with GNU sed, but not on OS X:
sed -i -e 's/foo/bar/' target.file
sed -i'' -e 's/foo/bar/' target.file
This works on OS X, but not with GNU sed:
sed -i '' -e 's/foo/bar/' target.file
On OS X you
can't use sed -i -e since the extension of the backup file would be set to -e
can't use sed -i'' -e for the same reasons—it needs a space between -i and ''.
When on OSX, I always install GNU sed version via Homebrew, to avoid problems in scripts, because most scripts were written for GNU sed versions.
brew install gnu-sed --with-default-names
Then your BSD sed will be replaced by GNU sed.
Alternatively, you can install without default-names, but then:
Change your PATH as instructed after installing gnu-sed
Do check in your scripts to chose between gsed or sed depending on your system
As Noufal Ibrahim asks, why can't you use Perl? Any Mac will have Perl, and there are very few Linux or BSD distributions that don't include some version of Perl in the base system. One of the only environments that might actually lack Perl would be BusyBox (which works like GNU/Linux for -i, except that no backup extension can be specified).
As ismail recommends,
Since perl is available everywhere I just do perl -pi -e s,foo,bar,g target.file
and this seems like a better solution in almost any case than scripts, aliases, or other workarounds to deal with the fundamental incompatibility of sed -i between GNU/Linux and BSD/Mac.
Answer: No.
The originally accepted answer actually doesn't do what is requested (as noted in the comments). (I found this answer when looking for the reason a file-e was appearing "randomly" in my directories.)
There is apparently no way of getting sed -i to work consistently on both MacOS and Linuces.
My recommendation, for what it is worth, is not to update-in-place with sed (which has complex failure modes), but to generate new files and rename them afterwards. In other words: avoid -i.
There is no way to have it working.
One way is to use a temporary file like:
TMP_FILE=`mktemp /tmp/config.XXXXXXXXXX`
sed -e "s/abc/def/" some/file > $TMP_FILE
mv $TMP_FILE some/file
This works on both
Here's another version that works on Linux and macOS without using eval and without having to delete backup files. It uses Bash arrays for storing the sed parameters, which is cleaner than using eval:
# Default case for Linux sed, just use "-i"
sedi=(-i)
case "$(uname)" in
# For macOS, use two parameters
Darwin*) sedi=(-i "")
esac
# Expand the parameters in the actual call to "sed"
sed "${sedi[#]}" -e 's/foo/bar/' target.file
This does not create a backup file, neither a file with appended quotes.
The -i option is not part of POSIX Sed. A more portable method would be
to use Vim in Ex mode:
ex -sc '%s/alfa/bravo/|x' file
% select all lines
s replace
x save and close
Steve Powell's answer is quite correct, consulting the MAN page for sed on OSX and Linux (Ubuntu 12.04) highlights the in-compatibility within 'in-place' sed usage across the two operating systems.
JFYI, there should be no space between the -i and any quotes (which denote an empty file extension) using the Linux version of sed, thus
sed Linux Man Page
#Linux
sed -i""
and
sed OSX Man page
#OSX (notice the space after the '-i' argument)
sed -i ""
I got round this in a script by using an alias'd command and the OS-name output of 'uname' within a bash 'if'. Trying to store OS-dependant command strings in variables was hit and miss when interpreting the quotes. The use of 'shopt -s expand_aliases' is necessary in order to expand/use the aliases defined within your script. shopt's usage is dealt with here.
Portable script for both GNU systems and OSX:
if [[ $(uname) == "Darwin" ]]; then
SP=" " # Needed for portability with sed
fi
sed -i${SP}'' -e "s/foo/bar/g" -e "s/ping/pong/g" foobar.txt
I ran into this problem. The only quick solution was to replace the sed in mac to the gnu version:
brew install gnu-sed
If you need to do sed in-place in a bash script, and you do NOT want the in-place to result with .bkp files, and you have a way to detect the os (say, using ostype.sh), -- then the following hack with the bash shell built-in eval should work:
OSTYPE="$(bash ostype.sh)"
cat > myfile.txt <<"EOF"
1111
2222
EOF
if [ "$OSTYPE" == "osx" ]; then
ISED='-i ""'
else # $OSTYPE == linux64
ISED='-i""'
fi
eval sed $ISED 's/2222/bbbb/g' myfile.txt
ls
# GNU and OSX: still only myfile.txt there
cat myfile.txt
# GNU and OSX: both print:
# 1111
# bbbb
# NOTE:
# if you just use `sed $ISED 's/2222/bbbb/g' myfile.txt` without `eval`,
# then you will get a backup file with quotations in the file name,
# - that is, `myfile.txt""`
The problem is that sed is a stream editor, therefore in-place editing is a non-POSIX extension and everybody may implement it differently. That means for in-place editing you should use ed for best portability. E.g.
ed -s foobar.txt <<<$',s/foo/bar/g\nw'
Also see https://wiki.bash-hackers.org/howto/edit-ed.
You can use sponge. Sponge is an old unix program, found in moreutils package (both in ubuntu and probably debian, and in homebrew in mac).
It will buffer all the content from the pipe, wait until the pipe is close (probably meaning that the input file is already close) and then overwrite:
From the man page:
Synopsis
sed '...' file | grep '...' | sponge file
The following works for me on Linux and OS X:
sed -i' ' <expr> <file>
e.g. for a file f containing aaabbaaba
sed -i' ' 's/b/c/g' f
yields aaaccaaca on both Linux and Mac. Note there is a quoted string containing a space, with no space between the -i and the string. Single or double quotes both work.
On Linux I am using bash version 4.3.11 under Ubuntu 14.04.4 and on the Mac version 3.2.57 under OS X 10.11.4 El Capitan (Darwin 15.4.0).
I need to replace first 4 header lines of only selected 250 erlang files (with extension .erl), but there are 400 erlang files in total in the directory+subdirectories, I need to avoid modifying the files which doesn't need the change.
I've the list of file names that are to be modified, but don't know how to make my linux command to make use of them.
sed -i '1s#.*#%% This Source Code Form is subject to the terms of the Mozilla Public#' *.erl
sed -i '2s#.*#%% License, v. 2.0. If a copy of the MPL was not distributed with this file,#' *.erl
sed -i '3s#.*#%% You can obtain one at http://mozilla.org/MPL/2.0/.#' *.erl
sed -i '4s#.*##' *.erl
in the above commands instead of passing *.erl I want to pass those list of file names which I need to modify, doing that one by one will take me more than 3 days to complete it.
Is there any way to do this?
Iterate over the shortlisted file names using awk and use xargs to execute the sed. You can execute multiple sed commands to a file using -e option.
awk '{print $1}' your_shortlisted_file_lists | xargs sed -i -e first_sed -e second_sed $1
xargs gets the file name from awk in a $1 variable.
Try this:
< file_list.txt xargs -1 sed -i -e 'first_cmd' -e 'second_cmd' ...
Not answering your question but a suggestion for improvement. Four sed commands for replacing header is inefficient. I would instead write the new header into a file and do the following
sed -i -e '1,3d' -e '4{r header' -e 'd}' file
will replace the first four lines of the file with header.
Another concern with your current s### approach is you have to watch for special chars \, & and your delimiter # in the text you are replacing.
You can apply the sed c (for change) command to each file of your list :
while read file; do
sed -i '1,4 c\
%% This Source Code Form is subject to the terms of the Mozilla Public\
%% License, v. 2.0. If a copy of the MPL was not distributed with this file,\
%% You can obtain one at http://mozilla.org/MPL/2.0/.\
' "$file"
done < filelist
Let's say you have a file called file_list.txt with all file names as content:
file1.txt
file2.txt
file3.txt
file4.txt
You can simply read all lines into a variable (here: files) and then iterate through each one:
files=`cat file_list.txt`
for file in $files; do
echo "do something with $file"
done
$ cat example.txt
Yields:
example
test
example
I want to remove 'test' string from this file.
$ grep -v test example.txt > example.txt
$ cat example.txt
$
The below works, but I have a feeling there is a better way!
$ grep -v test example.txt > example.txt.tmp;mv example.txt.tmp example.txt
$ cat example.txt
example
example
Worth noting that this is going to be on a file with over 10,000 lines.
Cheers
You could use sed,
sed -i '/test/d' example.txt
-i saves the changes made to that file. so you don't need to use a redirection operator.
-i[SUFFIX], --in-place[=SUFFIX]
edit files in place (makes backup if SUFFIX supplied)
You're doing it the right way but use an && before the mv to make sure the grep succeeded or you'll zap your original file:
grep -F -v test example.txt > example.txt.tmp && mv example.txt.tmp example.txt
I also added the -F options since you said you want to remove a string, not a regexp.
You COULD use sed -i but then you need to worry about figuring out and/or escaping sed delimiters and sed does not support searching for strings so you'd need to try to escape every possible combination of regexp characters in your search string to try to make sed treat them as literal chars (a process you CANNOT automate due to the position-sensitive nature of regexp chars) and all it'd save you is manually naming your tmp file since sed uses one internally anyway.
Oh, one other option - you could use GNU awk 4.* with "inplace editing". It also uses a tmp file internally like sed does but it does support string operations so you don't need to try to escape RE metacharacters and it doesn't have delimiters as part of the syntax to worry about:
awk -i inplace -v rmv="test" '!index($0,rmv)' example.txt
Any grep/sed/awk solution will run the in blink of an eye on a 10,000 line file.
Is it possible to search in a file using shell and then replace a value? When I install a service I would like to be able to search out a variable in a config file and then replace/insert my own settings in that value.
Sure, you can do this using sed or awk. sed example:
sed -i 's/Andrew/James/g' /home/oleksandr/names.txt
You can use sed to perform search/replace. I usually do this from a bash shell script, and move the original file containing values to be substituted to a new name, and run sed writing the output to my original file name like this:
#!/bin/bash
mv myfile.txt myfile.txt.in
sed -e 's/PatternToBeReplaced/Replacement/g' myfile.txt.in > myfile.txt.
If you don't specify an output, the replacement will go to stdout.
sed -i 's/variable/replacement/g' *.conf
You can use sed to do this:
sed -i 's/toreplace/yoursetting/' configfile
sed is probably available on every unix like system out there. If you want to replace more than one occurence you can add a g to the s-command:
sed -i 's/toreplace/yoursetting/g' configfile
Be careful since this can completely destroy your configfile if you don't specify your toreplace-value correctly. sed also supports regular expressions in searching and replacing.
Look at the UNIX power tools awk, sed, grep and in-place edit of files with Perl.
filepath="/var/start/system/dir1"
searchstring="test"
replacestring="test01"
i=0;
for file in $(grep -l -R $searchstring $filepath)
do
cp $file $file.bak
sed -e "s/$searchstring/$replacestring/ig" $file > tempfile.tmp
mv tempfile.tmp $file
let i++;
echo "Modified: " $file
done
Generally a tool like awk or sed are used for this.
$ sed -i 's/ugly/beautiful/g' /home/bruno/old-friends/sue.txt
I have a text file with a bunch of file paths such as -
web/index.erb
web/contact.erb
...
etc. I need to append before the
</head>
a line of code, to every single file, I'm trying to figure out how to do this without opening each file of course. I've heard sed, but I've never used it before..was hoping there would be a grep command maybe?
Thanks
xargs can be used to apply sed (or any other command) to each filename or argument in a list. So combining that with Rom1's answer gives:
xargs sed -i 's/<\/html>/myline\n<\/html>/g' < fileslist.txt
while read f ; do
sed -i '/<\/head>/i*iamthelineofcode*' "$f"
done <iamthefileoffiles.list
or
sed -i '/<\/head>/i*iamthelineofcode*' $(cat iamthefileoffiles.list)