I have a parameter name like
PAR="DBS_OUT"
and I have a text file(Repla.txt) with below values:
DB_TECH
DB_ADMIN
DB_TERA
DB_APS
These values in the files can defer but the parameter value will remain the same.
Now I have some Unix shell script where I need to find all such values mentioned in the file (Repla.txt)
and replace them with the parameter (PAR). Since the values in the Repla.txt is not fixed I am not able to use the sed command. for eg:
sed 's/old/new/g' input.txt > output.txt
Can anyone please help me.
Thanks
I'm not sure I completely understand what you are trying to do but if you are trying to use the values contained in Repla.txt as the strings that you want to replace in other files then the following bash line will do what you want:
PAR="DBS_OUT"; for FIND in `cat Repla.txt`; do $( find /path/to/files -name 'test?.txt' -exec sed -i "s/$FIND/$PAR/g" '{}' \;); done;
It will replace the strings contained in Repla.txt with the string DBS_OUT in all files that match test?.txt in the dir (and subdirs) /path/to/files. You will need to understand how find works.
Also note that I am not telling sed to backup, you probably want to test this out on some test files before you execute it for real. Hopefully you also have your scripts in source control so its not a big deal if you mess things up.
I hope your replacement on Capital letters only.
sed 's/DBS_[A-Z]*/DBS_OUT/g' repla.txt > destination file
or
sed 's/DBS_[A-Z]*/DBS_OUT/g' repla.txt
Related
I have a project directory with folders containing .html files. I want to find those files which have the pattern -
'btn-primary.*{.*Save'
And replace the
'btn-primary' word with 'btn-primary Save'
only in those lines.
What I have done:
grep -rl -e 'btn-primary.*{Save' . |xargs sed -i 's/btn-primary/btn-primary Save/g'
What this did:
This found all files that have that pattern, that's okay. Then, sed ran on all of those files and replaced 'btn-primary' with 'btn-primary save' wherever it got - which is not what I want
What I want: to replace on those lines where there is 'Save' somewhere after 'btn-primary'.
Any help will be very much appreciated.
Regards,
Rahul
Why are you using grep at all? Sed does pattern matching:
sed -e 's/btn-primary\(.*{.*Save\)/btn-primary Save\1/g'
or:
sed -e 's/\(btn-primary\)\(.*{.*Save\)/\1 Save\2/g'
If you are using grep to try to trim down the number of files that sed will operate on, you're fooling yourself if you believe that is more efficient. By doing that, you will read every file that doesn't match only once, but every file that does match will be read twice. If you only use sed, every file will be read only once.
I have come across unix sed command usage and not able to understand what it does. Could you please help me to understand the usage ? If possible please share some reference to understand such usages of sed command.
sed -i '/^export JAVA_HOME/ s:.*:export JAVA_HOME=/usr/java/default\nexport HADOOP_PREFIX=/usr/local/hadoop\nexport HADOOP_HOME=/usr/local/hadoop\n:' $HADOOP_PREFIX/etc/hadoop/hadoop-env.sh
The command is simple, though it assumes GNU sed because of the way it uses the -i option; for macOS Sierra and related systems, you'd need to use -i '' in place of just -i.
Overall, it corresponds to:
sed -i '/Pattern/ s:.*:Replacement:' file
where:
-i means overwrite each input file with its edited output without creating a backup copy.
/Pattern/ is ^export JAVA_HOME; a line starting with the word export and then JAVA_HOME separated by a single space.
s:.*:Replacement: is a substitute command, using : instead of the more conventional / (often s/.*/Replacement/) as the pattern delimiter. This is done because the replacement text contains slashes. The .* matches the whole line. The rest of the material is written in place of the original export JAVA_HOME line. The \n sequence expands to a newline, so it actually produces a number of lines in the output.
file is $HADOOP_PREFIX/etc/hadoop/hadoop-env.sh
As others have pointed out, this is a sed command invocation. The command is short for "Stream EDitor" and is quite useful for modifying files programaticallly. Your best bet is to read the man pages (man sed, but I've broken down your particular command here for instructive purposes:
sed # The command
-i # Edit file in place (no backup)
'/^export JAVA_HOME/ # For every line that begins with 'export JAVA_HOME'...
s: # substitue...
.*: # the entire line with...
export JAVA_HOME=/usr/java/default
export HADOOP_PREFIX=/usr/local/hadoop
export HADOOP_HOME=/usr/local/hadoop
:' # End of command
$HADOOP_PREFIX/etc/hadoop/hadoop-env.sh # Run on the following file
Points of interest:
Commands can be limited to a particular address range or scope. Here, the scope was a search.
The substitue command can be delimited by almost any character (usually it is /, but in this case, : was chosen to prevent escaping of the / in the filepaths
The sed expression was enclosed in ' to prevent shell expansion of variables. Although no expansions would have taken place in this scenario, it is fairly common to see the expression wrapped in ' to eliminate the possibility.
I have a file with name
ROCKET_25_08:00.csv
I want to trim the name of the file to
ROCKET_25_.csv
I tried mv but mv is not what I required because there will be cases where the files may be more than one.
I want the name till the second _.
How to get that in unix.
Please advise.
There are some utilities that provide more flexible renaming. But one solution that won't use anything other but included UNIX tools (like sed) would be:
ls -d * | sed -re 's/^([^_]*_[^_]*_)(.*)(\....)$/mv -v \1\2\3 \1\3/' | bash
This will only work in one directory, it won't process subdirectories.
It's not at all clear what you are actually trying to do, but if you just want to remove text between the last underscore and the period, you can do:
f=ROCKET_25_08:00.csv
echo ${f%_*}_.csv
I use grep to sort log big file into small one but still there is long dir path in output log file which is common every time.I have to do find and replace every time.
Isnt there any way i can grep -r "format" log.log | execute findnreplce thing?
Sed will do what you want. Basic syntax to replace all the matches of foo with bar in-place in $file is:
sed -i 's/foo/bar/g' $file
If you're just wanting to delete rather than replace, simply leave out the 'bar' (so s/foo//g).
See this tutorial for a lot more detail, such as regex support.
sed -n '/match/s/pattern/repl/p'
Will print all the lines that match the regex match, with all instances of pattern replaced by repl. Since your lines may contain paths, you will probably want to use a different delimeter. / is customary, but you can also do:
sed -n '\#match#s##repl#p`
In the second case, omitting pattern will cause match to be used for the pattern to be replaced.
I found this command line search and replace example:
find . -type f -print0 | xargs -0 sed -i 's/find/replace/g'
It worked fine except it changed the date and file ownership on EVERY file it searched through, even those that did not contain the search text.
What's a better solution to this task?
Using the -c option (if you are on Linux) ought to cause sed to preserve ownership. As you are using the command, it is in fact rewriting every file, even though it is not making changes to the files that do not contain find.
The easiest way to fix that would be to only execute sed on the files if the contain the text by using grep first:
find . -type f | while read file; do
grep -q find $file && sed -i 's/find/replace/g' $file
done
This does require reading each file twice (in the worst case), so it might be a little slower. Hopefully, though, your OS should keep the file in its disk cache, so you shouldn't see much of a slowdown, since this process is definitely I/O-bound, not CPU-bound.
Some distro's versions of sed (namely, RedHat and family) have added a -c option that accomplishes this, in which case see #Isaac's answer.
But for those with an unpatched GNU sed, the easiest way I've found is to simply substitute with perl, which rewrites files similar to sed -c when available. The following commands are basically equivalent:
sed -ci 's/find/replace/'
perl -pi -e 's/find/replace/'
Just don't get too excited and do perl -pie; like with sed -ie, instead of interpreting as another option, it will use e as an argument to -i, and use it as a suffix to backup the original file. See perldoc perlrun for more details there.
Perl's regex parsing is a little different from sed (better, imo) for more complicated things: generally speaking, use less backslashes.