SED command in UNIX - unix

I want to remove below string from a file in Unix:
<?xml version='1.0' encoding='UTF-8'?>
The file content is exactly this:
<?xml version='1.0' encoding='UTF-8'?>Hello World
in one single continuous line.
I am using the following command to achieve the same:
sed s'/<?xml version='1.0' encoding='UTF-8'?>//g' myFile > myFile1
However, the resultant file myFile1 is still having the string.
How to achieve this ?


Given that it's the XML declaration line is this the first line in the file(s)? If so, you can remove the first line like this:
sed -i "1d" <filename>
The -i edits the file in place so will overwrite your original, while the "1d" command simply deletes a line.
However, if it's not the first line, or appears multiple times, then you can use this:
sed -i '/\?xml/d' <filename>
Again, it's editing in place and using the d command to delete, but this time it's deleting based on the regular expression. You might want to expand the regex a bit so that it's more targeted, but the principle is there.
You say in the comments that it's just part of a line that you want to remove, so in that case:
sed -i "s/<?xml .*?\?>//" <filename>
Summed up as "replace everything between "" with nothing (effectively delete it).


Use double quotes for the outer quotes to avoid the escape issue:
sed "s/<?xml version='1.0' encoding='UTF-8'?>//g" myFile > myFile1


If you search for "string" in a directory, it should give you the top 3 and bottom 3 occurrences of the string in all the files, and output that to an out file.
I am using:
grep string path-to-file | head -3 > out.log
grep string path-to-file | tail -3 >> out.log


sed '/<?xml version='1.0' encoding='UTF-8'?>/d' myfile .


Apart from the issue with the quotes, you might consider using grep -v instead of sed:
grep -v "<?xml version='1.0' encoding='UTF-8'?>" myFile > myFile1
But if you know that the line you don't want is always the first line in the file, the following is even easier:
tail -n +2 myFile > myFile1


Please find the below script.
sed 's/\<\?xml version\=\'1\.0\' encoding\=\'UTF\-8\'\?\>//g' myfile > myfile_new
Idea is to comment the special characters.


sed -e 's/<[^>]*>//g' myfile should work

Related

How to read a value from recursive xml attribute in Unix using sed/awk/grep only

I have config.xml. Here I need to retrieve the value of the attribute from the xpath
/domain/server/name
I can only use grep/sed/awk. Need Help
The content of the xml is below where I need to retrieve the Server Name only.
<domain>
<server>
<name>AdminServer</name>
<port>1234</port>
</server>
<server>
<name>M1Server</name>
<port>5678</port>
</server>
<machine>
<name>machine01</name>
</machine>
<machine>
<name>machine02</name>
</machine>
</domain>
The output should be :
AdminServer
M1Server
I tried to do,
sed -ne '/<\/name>/ { s/<[^>]*>(.*)<\/name>/\1/; p }' config.xml

sed is only for simple substitutions on individual lines, doing anything else with sed is strictly for mental exercise, not for real code. That's not what you are trying to do so you shouldn't even be considering sed. Just use awk:
$ awk -F'[<>]' 'p=="server" && $2=="name"{print $3} {p=$2}' file
AdminServer
M1Server
That will work with any awk on any UNIX box. If that's not all you need then edit your question to provide more truly representative sample input and expected output.

Try this command. Name your xml and supply that file as an input.
awk '/<server>/,/<\/server>/' < name.xml | grep "name" | cut -d ">" -f2 | cut -d "<" -f1
OutPut:
AdminServer
M1Server

Based on your sample Input_file shown, could you please try following.
awk -F"[><]" '/<\/server>/{a="";next} /<server>/{a=1;next} a && /<name>/{print $3}' Input_file

sed -n '/<server>/{n;s/\s*<[^>]*>//gp}'
for example. for the first match
1. /<server>/
match the line that contains "<server>" got " <server>"
2. n
the "n" command will go to next line. after executed "n" command got " <name>AdminServer</name>"
3.s/\s*<[^>]*>//gp
replece all "\s*<[^>]*>" as "". then print the pattern space
type "info sed" for more sed command

You can get the desired output with just sed:
sed -n 's:.*<name>\(.*\)</name>.*:\1:p' config.xml

I feel dirty parsing XML in awk.
The following finds the correct depth of entry with the right tag name. It does not verify the path, though it depends on the elements you specified. While this works on your example data, it makes certain ugly assumptions and it's not guaranteed to work elsewhere:
awk -F'[<>]' '$2~/^(domain|server|name)$/{n++} $1~/\// {n--} n==3&&$2=="name"{print $3}' input.xml
A better solution would be to parse the XML itself.
$ awk -F'[<>]' -v check="domain.server.name" '$2~/^[a-z]/ { path=path "." $2; closex="</"$2">" } $0~closex { sub(/\.[^.]$/,"",path) } substr(path,2)==check {print path " = " $3}' input.xml
.domain.server.name = AdminServer
Here it is split out for easier commenting.
$ awk -F'[<>]' -v check="domain.server.name" '
# Split fields around pointy brackets. Supply a path to check.
$2~/^[a-z]/ { # If we see an open tag,
path=path "." $2 # append the current tag to our path,
closex="</"$2">" # compose a close tag which we'll check later.
}
$0~closex { # If we see a close tag,
sub(/\.[^.]$/,"",path) # truncate the path.
}
substr(path,2)==check { # If we match the given path,
print path " = " $3 # print the result.
}
' input.xml
Note that this solution barfs horribly if you feed it badly formatted XML. The recognition of tags could be improved, but may be sufficient if you have consistently formatted XML. It may barf horribly for other reasons too. Do not do this. Install the correct tools to parse XML properly.

How to remove blank lines from a Unix file

I need to remove all the blank lines from an input file and write into an output file. Here is my data as below.
11216,33,1032747,64310,1,0,0,1.878,0,0,0,1,1,1.087,5,1,1,18-JAN-13,000603221321
11216,33,1033196,31300,1,0,0,1.5391,0,0,0,1,1,1.054,5,1,1,18-JAN-13,059762153003
11216,33,1033246,31300,1,0,0,1.5391,0,0,0,1,1,1.054,5,1,1,18-JAN-13,000603211032
11216,33,1033280,31118,1,0,0,1.5513,0,0,0,1,1,1.115,5,1,1,18-JAN-13,055111034001
11216,33,1033287,31118,1,0,0,1.5513,0,0,0,1,1,1.115,5,1,1,18-JAN-13,000378689701
11216,33,1033358,31118,1,0,0,1.5513,0,0,0,1,1,1.115,5,1,1,18-JAN-13,000093737301
11216,33,1035476,37340,1,0,0,1.7046,0,0,0,1,1,1.123,5,1,1,18-JAN-13,045802041926
11216,33,1035476,37340,1,0,0,1.7046,0,0,0,1,1,1.123,5,1,1,18-JAN-13,045802041954
11216,33,1035476,37340,1,0,0,1.7046,0,0,0,1,1,1.123,5,1,1,18-JAN-13,045802049326
11216,33,1035476,37340,1,0,0,1.7046,0,0,0,1,1,1.123,5,1,1,18-JAN-13,045802049383
11216,33,1036985,15151,1,0,0,1.4436,0,0,0,1,1,1.065,5,1,1,18-JAN-13,000093415580
11216,33,1037003,15151,1,0,0,1.4436,0,0,0,1,1,1.065,5,1,1,18-JAN-13,000781202001
11216,33,1037003,15151,1,0,0,1.4436,0,0,0,1,1,1.065,5,1,1,18-JAN-13,000781261305
11216,33,1037003,15151,1,0,0,1.4436,0,0,0,1,1,1.065,5,1,1,18-JAN-13,000781603955
11216,33,1037003,15151,1,0,0,1.4436,0,0,0,1,1,1.065,5,1,1,18-JAN-13,000781615746

sed -i '/^$/d' foo
This tells sed to delete every line matching the regex ^$ i.e. every empty line. The -i flag edits the file in-place, if your sed doesn't support that you can write the output to a temporary file and replace the original:
sed '/^$/d' foo > foo.tmp
mv foo.tmp foo
If you also want to remove lines consisting only of whitespace (not just empty lines) then use:
sed -i '/^[[:space:]]*$/d' foo
Edit: also remove whitespace at the end of lines, because apparently you've decided you need that too:
sed -i '/^[[:space:]]*$/d;s/[[:space:]]*$//' foo

awk 'NF' filename
awk 'NF > 0' filename
sed -i '/^$/d' filename
awk '!/^$/' filename
awk '/./' filename
The NF also removes lines containing only blanks or tabs, the regex /^$/ does not.

Use grep to match any line that has nothing between the start anchor (^) and the end anchor ($):
grep -v '^$' infile.txt > outfile.txt
If you want to remove lines with only whitespace, you can still use grep. I am using Perl regular expressions in this example, but here are other ways:
grep -P -v '^\s*$' infile.txt > outfile.txt
or, without Perl regular expressions:
grep -v '^[[:space:]]*$' infile.txt > outfile.txt

sed -e '/^ *$/d' input > output
Deletes all lines which consist only of blanks (or is completely empty). You can change the blank to [ \t] where the \t is a representation for tab. Whether your shell or your sed will do the expansion varies, but you can probably type the tab character directly. And if you're using GNU or BSD sed, you can do the edit in-place, if that's what you want, with the -i option.
If I execute the above command still I have blank lines in my output file. What could be the reason?
There could be several reasons. It might be that you don't have blank lines but you have lots of spaces at the end of a line so it looks like you have blank lines when you cat the file to the screen. If that's the problem, then:
sed -e 's/ *$//' -e '/^ *$/d' input > output
The new regex removes repeated blanks at the end of the line; see previous discussion for blanks or tabs.
Another possibility is that your data file came from Windows and has CRLF line endings. Unix sees the carriage return at the end of the line; it isn't a blank, so the line is not removed. There are multiple ways to deal with that. A reliable one is tr to delete (-d) character code octal 15, aka control-M or \r or carriage return:
tr -d '\015' < input | sed -e 's/ *$//' -e '/^ *$/d' > output
If neither of those works, then you need to show a hex dump or octal dump (od -c) of the first two lines of the file, so we can see what we're up against:
head -n 2 input | od -c
Judging from the comments that sed -i does not work for you, you are not working on Linux or Mac OS X or BSD — which platform are you working on? (AIX, Solaris, HP-UX spring to mind as relatively plausible possibilities, but there are plenty of other less plausible ones too.)
You can try the POSIX named character classes such as sed -e '/^[[:space:]]*$/d'; it will probably work, but is not guaranteed. You can try it with:
echo "Hello World" | sed 's/[[:space:]][[:space:]]*/ /'
If it works, there'll be three spaces between the 'Hello' and the 'World'. If not, you'll probably get an error from sed. That might save you grief over getting tabs typed on the command line.

grep . file
grep looks at your file line-by-line; the dot . matches anything except a newline character. The output from grep is therefore all the lines that consist of something other than a single newline.

with awk
awk 'NF > 0' filename

To be thorough and remove lines even if they include spaces or tabs something like this in perl will do it:
cat file.txt | perl -lane "print if /\S/"
Of course there are the awk and sed equivalents. Best not to assume the lines are totally blank as ^$ would do.
Cheers

You can sed's -i option to edit in-place without using temporary file:
sed -i '/^$/d' file

Delete empty lines from a file

I need to delete empty lines from a file (with spaces only - not null records).
The following command works only for null rows, but not in case of
spaces:
sed '/^$/d' filename
Can it be done using grep?

Use \s* for blank lines containing only whitespace:
sed '/^\s*$/d' file
To save the changes back to the file use the -i option:
sed -i '/^\s*$/d' file
Edit:
The regex ^\s*$ matches a line that only contains whitespace, grep -v print lines that don't match a given pattern so the following will print all none black lines:
grep -v '^\s*$' file

The POSIX portable way to do this is
sed -i '/^[[:blank:]]*$/d' file
or
grep -v '^[[:blank:]]*$' file

sed -i '/^[ \t]*$/d' file-name
it will delete all blank lines having any no. of white spaces (spaces or tabs) i.e. (0 or more)in the file..
NOte: there is a 'space' followed by '\t' inside the square bracket...
"-i" will force to write the updated contents back in the file... without this flag you can see the empty lines got deleted on the screen but the actual file will not be affected.

It happened that the file was copied from Windows machine a the sed command (sed '/^$/d' foo ) was not running correctly.
I ran following command and it worked.
$ dos2unix foo

Why sed removes last line?

$ cat file.txt
one
two
three
$ cat file.txt | sed "s/one/1/"
1
two
Where is the word "three"?
UPDATED:
There is no line after the word "three".

As Ivan suggested, your text file is missing the end of line (EOL) marker on the final line. Since that's not present, three is printed out by sed but then immediately over-written by your prompt. You can see it if you force an extra line to be printed.
sed 's/one/1/' file.txt && echo
This is a common problem since people incorrectly think of the EOL as an indication that there's a following line (which is why it's commonly called a "newline") and not as an indication that the current line has ended.

Using comments from other posts:
older versions of sed do not process the last line of a file if no EOL or "new line" is present.
echo can be used to add a new line
Then, to solve the problem you can re-order the commands:
( cat file.txt && echo ) | sed 's/one/1/'

I guess there is no new line character after last line. sed didn't find line separator after last line and ignore it.
Update
I suggest you to rewrite this in perl (if you have it installed):
cat file.txt | perl -pe 's/one/1/'

Instead of cat'ing the file and piping into sed, run sed with the file name as an argument after the substitution string, like so:
sed "s/one/1/" file.txt
When I did it this way, I got the "three" immediately following by the prompt:
1
two
three$

A google search shows that the man page for some versions of sed (not the GNU or BSD versions, which work as you'd expect) indicate that it won't process an incomplete line (one that's not newline-terminated) at the end of a file. The solution is to ensure your files end with a newline, install GNU sed, or use awk or perl instead.

here's an awk solution
awk '{gsub("one","1")}1' file.txt

Replace \n with \r\n in Unix file

I'm trying to do the opposite of this question, replacing Unix line endings with Windows line endings, so that I can use SQL Server bcp over samba to import the file. I have sed installed but not dos2unix. I tried reversing the examples but to no avail.
Here's the command I'm using.
sed -e 's/\n/\r\n/g' myfile
I executed this and then ran od -c myfile, expecting to see \r\n where there used to be \n. But there all still \n. (Or at least they appear to be. The output of od overflows my screen buffer, so I don't get to see the beginning of the file).
I haven't been able to figure out what I'm doing wrong. Any suggestions?

When faced with this, I use a simple perl one-liner:
perl -pi -e 's/\n/\r\n/' filename
because sed behavior varies, and I know this works.

What is the problem with getting dos2unix onto the machine?
What is the platform you are working with?
Do you have GNU sed or regular non-GNU sed?
On Solaris, /usr/bin/sed requires:
sed 's/$/^M/'
where I entered the '^M' by typing controlV controlM. The '$' matches at the end of the line, and replaces the end of line with the control-M. You can script that, too.
Mechanisms expecting sed to expand '\r' or '\\r' to control-M are going to be platform-specific, at best.

You don't need the -e option.
$ matches the endline character. This sed command will insert a \r character before the end of line:
sed 's/$/\r/' myfile

Just adding a \r (aka ^M, see Jonathan Leffler's answer) in front of \n is not safe because the file might have mixed mode EOL, so then you risk ending up with some lines becomming \r\r\n. The safe thing to do is first remove all '\r' characters, and then insert (a single) \r before \n.
#!/bin/sh
sed 's/^M//g' ${1+"$#"} | sed 's/$/^M/'
Updated to use ^M.

sed 's/\([^^M]\)$/\0^M/' your_file
This makes sure you only insert a \r when there is no \r before \n. This worked for me.

Try using:
echo " this is output" > input
sed 's/$/\r/g' input |od -c

Maybe if you try it this way
cat myfile | sed 's/\n/\r\n/g' > myfile.win
will work, from my understanding your just making the replacements to the console output, you need to redirect output to a file, in this case myfile.win, then you could just rename it to whatever you want. The whole script would be (running inside a directory full of this kind of files):
#!/bin/bash
for file in $(find . -type f -name '*')
do
cat $file | sed 's/\n/\r\n/g' > $file.new
mv -f $file.new $file
done

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