How to add newline after delimiter in Unix? - linux

Below is my input
54.243.94.244, 54.243.113.63
and I want the out like below,
54.243.94.244
54.243.113.63
i.e. after comma I need to add newline.
How to achieve it in Unix? Please suggest some commands.

Another option is tr
tr ',' '\n'

sed will do the trick:
$ echo '54.243.94.244, 54.243.113.63' | sed 's/, /\n/g'
54.243.94.244
54.243.113.63
The sed command s/, /\n/g will replace all occurrences of a comma followed by a space in the input with a newline.

A simple example would be
VAR1=a
VAR1="$VAR1"$'\n'b
echo "$VAR"
This would give output like
a
b

Related

unescaped newline inside substitute pattern in sed variable [duplicate]

Here are my attempts to replace a b character with a newline using sed while running bash
$> echo 'abc' | sed 's/b/\n/'
anc
no, that's not it
$> echo 'abc' | sed 's/b/\\n/'
a\nc
no, that's not it either. The output I want is
a
c
HELP!
Looks like you are on BSD or Solaris. Try this:
[jaypal:~/Temp] echo 'abc' | sed 's/b/\
> /'
a
c
Add a black slash and hit enter and complete your sed statement.
$ echo 'abc' | sed 's/b/\'$'\n''/'
a
c
In Bash, $'\n' expands to a single quoted newline character (see "QUOTING" section of man bash). The three strings are concatenated before being passed into sed as an argument. Sed requires that the newline character be escaped, hence the first backslash in the code I pasted.
You didn't say you want to globally replace all b. If yes, you want tr instead:
$ echo abcbd | tr b $'\n'
a
c
d
Works for me on Solaris 5.8 and bash 2.03
In a multiline file I had to pipe through tr on both sides of sed, like so:
echo "$FILE_CONTENTS" | \
tr '\n' ¥ | tr ' ' ∑ | mySedFunction $1 | tr ¥ '\n' | tr ∑ ' '
See unix likes to strip out newlines and extra leading spaces and all sorts of things, because I guess that seemed like the thing to do at the time when it was made back in the 1900s. Anyway, this method I show above solves the problem 100%. Wish I would have seen someone post this somewhere because it would have saved me about three hours of my life.
echo 'abc' | sed 's/b/\'\n'/'
you are missing '' around \n

Trying to use grep to find something, then output a different part of the line

Say for instance I'm searching a line that is like this:
Color asdf
and I use grep to find that line, like grep asdf file.txt
How would I then display Color? Learning linux is hard.
With the command line tool sed you can replace stings by using regular expressions:
echo "Color asdf" | sed 's/\([^ ]*\).*/\1/'
This part: \([^ ]*\).* is a regular expresion. The first part of the regex: [^ ]*, matches any character except a space as many times as possible and what's between the \( and \) is being captured in the variable \1. Then you also match the remaining part of the string with .* and replace all of that with only the first word which was captured by \([^ ]*\) by using \1 in the replace part of the sed command.
Here some more info about sed:
http://linux.about.com/od/commands/a/Example-Uses-Of-Sed-Cmdsedxa.htm
You could use sed:
sed -n 's/[[:space:]][[:space:]]*asdf$//p' file.txt
Details:
The -n option tells sed not to print the pattern space automatically. Basically, it doesn't output anything unless you tell it to.
The s command of sed replaces text. Here, if a line ends with asdf, preceded by at least one whitespace character, we replace all of that with nothing and then print the line (notice the p flag at the end of the s command). The printing is only done if something was actually replaced. More information about the s command can be found e. g. in the GNU sed manual.
Edit for clarity: When using single quotes, parameter expansion does not work and thus, variables won't be replaced. To use variables, use double quotes:
search=asdf
sed -n "s/[[:space:]][[:space:]]*${search}\$//p" file.txt
If you'd really like to use grep here, you could pipe the output from grep into cut:
grep -h asdf *.txt | cut -s -d -f 1
Note that there have to be two spaces after the -d option to cut - the first tells cut to use a blank as the field delimiter (I'm assuming your fields are blank-delimited rather than tab-delimited), while the second separates the -d option from the following option (-f).
But, yeah, sed or awk are probably your friends here... :-)
you can color pattern in the line using grep
grep --colour -o 'asdf' file.txt
edit: the -o option will print only the patterns

Linux sed, how to delete the rest of the word?

Suppose I have text.txt:
342423423423 - 'namefile.jpg' saved (2423423kb/2423423kb)
I can use
sed 's/^.*- //' text.txt
the output will be:
'namefile.jpg' saved (2423423kb/2423423kb)
it will get rid the text at the beginning of that namefile.jpg, but what if I also want to get rid the rest of it ? I want the output to be like this:
'namefile.jpg'
What sed pattern should I use? Please note that after the 'namefile.jpg' the text isn't always the same. It changes from time to time.
You could use capturing groups.
sed 's/^.*- \([^ ]\+\).*/\1/' text.txt
OR
sed 's/^.*- //;s/ .*//' file
^.*- regex matches all the characters from the start upto -. And the first command replaces all the matches characters with an empty string.
.* Now from the resultant string, this regex would match all the characters from the first space upto the last. Replacing those characters with an empty string will gave you the desired output.
Example:
$ echo "342423423423 - 'namefile.jpg' saved (2423423kb/2423423kb" | sed 's/^.*- \([^ ]\+\).*/\1/'
'namefile.jpg'
$ echo "342423423423 - 'namefile.jpg' saved (2423423kb/2423423kb" | sed 's/^.*- //;s/ .*//'
'namefile.jpg'
Or with awk:
echo "342423423423 - 'namefile.jpg' saved (2423423kb/2423423kb)" | awk '{print $3}'
Default delimiter for awk is space. Just print the 3rd field.
Try this way also
sed "s/.*\('.*'\).*/\1/" FileName
Output :
'namefile.jpg'
This is not sed but show how to do it with awk
awk -F\' '{print $2}' text.txt
namefile.jpg
or if you like to have the single quotes.
awk -F\' '{print FS$2FS}' text.txt
'namefile.jpg'
Just use a simple cut command
cut -d ' ' -f3 text.txt
or you can also use this,
sed 's/^.*- //' text.txt|cut -d ' ' -f1
Both will give you this Output:
'namefile.jpg'

How do I replace single quotes with another character in sed?

I have a flat file where I have multiple occurrences of strings that contains single quote, e.g. hari's and leader's.
I want to replace all occurrences of the single quote with space, i.e.
all occurences of hari's to hari s
all occurences of leader's to leader s
I tried
sed -e 's/"'"/ /g' myfile.txt
and
sed -e 's/"'"/" "/g' myfile.txt
but they are not giving me the expected result.
Try to keep sed commands simple as much as possible.
Otherwise you'll get confused of what you'd written reading it later.
#!/bin/bash
sed "s/'/ /g" myfile.txt
This will do what you want to
echo "hari's"| sed 's/\x27/ /g'
It will replace single quotes present anywhere in your file/text. Even if they are used for quoting they will be replaced with spaces. In that case(remove the quotes within a word not at word boundary) you can use the following:
echo "hari's"| sed -re 's/(\<.+)\x27(.+\>)/\1 \2/g'
HTH
Just go leave the single quote and put an escaped single quote:
sed 's/'\''/ /g' input
also possible with a variable:
quote=\'
sed "s/$quote/ /g" input
Here is based on my own experience.
Please notice on how I use special char ' vs " after sed
This won't do (no output)
2521 #> echo 1'2'3'4'5 | sed 's/'/ /g'
>
>
>
but This would do
2520 #> echo 1'2'3'4'5 | sed "s/'/ /g"
12345
The -i should replace it in the file
sed -i 's/“/"/g' filename.txt
if you want backups you can do
sed -i.bak 's/“/"/g' filename.txt
I had to replace "0x" string with "32'h" and resolved with:
sed 's/ 0x/ 32\x27h/'

Delete empty lines using sed

I am trying to delete empty lines using sed:
sed '/^$/d'
but I have no luck with it.
For example, I have these lines:
xxxxxx
yyyyyy
zzzzzz
and I want it to be like:
xxxxxx
yyyyyy
zzzzzz
What should be the code for this?
You may have spaces or tabs in your "empty" line. Use POSIX classes with sed to remove all lines containing only whitespace:
sed '/^[[:space:]]*$/d'
A shorter version that uses ERE, for example with gnu sed:
sed -r '/^\s*$/d'
(Note that sed does NOT support PCRE.)
I am missing the awk solution:
awk 'NF' file
Which would return:
xxxxxx
yyyyyy
zzzzzz
How does this work? Since NF stands for "number of fields", those lines being empty have 0 fields, so that awk evaluates 0 to False and no line is printed; however, if there is at least one field, the evaluation is True and makes awk perform its default action: print the current line.
sed
'/^[[:space:]]*$/d'
'/^\s*$/d'
'/^$/d'
-n '/^\s*$/!p'
grep
.
-v '^$'
-v '^\s*$'
-v '^[[:space:]]*$'
awk
/./
'NF'
'length'
'/^[ \t]*$/ {next;} {print}'
'!/^[ \t]*$/'
sed '/^$/d' should be fine, are you expecting to modify the file in place? If so you should use the -i flag.
Maybe those lines are not empty, so if that's the case, look at this question Remove empty lines from txtfiles, remove spaces from start and end of line I believe that's what you're trying to achieve.
I believe this is the easiest and fastest one:
cat file.txt | grep .
If you need to ignore all white-space lines as well then try this:
cat file.txt | grep '\S'
Example:
s="\
\
a\
b\
\
Below is TAB:\
\
Below is space:\
\
c\
\
"; echo "$s" | grep . | wc -l; echo "$s" | grep '\S' | wc -l
outputs
7
5
Another option without sed, awk, perl, etc
strings $file > $output
strings - print the strings of printable characters in files.
With help from the accepted answer here and the accepted answer above, I have used:
$ sed 's/^ *//; s/ *$//; /^$/d; /^\s*$/d' file.txt > output.txt
`s/^ *//` => left trim
`s/ *$//` => right trim
`/^$/d` => remove empty line
`/^\s*$/d` => delete lines which may contain white space
This covers all the bases and works perfectly for my needs. Kudos to the original posters #Kent and #kev
The command you are trying is correct, just use -E flag with it.
sed -E '/^$/d'
-E flag makes sed catch extended regular expressions. More info here
You can say:
sed -n '/ / p' filename #there is a space between '//'
You are most likely seeing the unexpected behavior because your text file was created on Windows, so the end of line sequence is \r\n. You can use dos2unix to convert it to a UNIX style text file before running sed or use
sed -r "/^\r?$/d"
to remove blank lines whether or not the carriage return is there.
This works in awk as well.
awk '!/^$/' file
xxxxxx
yyyyyy
zzzzzz
You can do something like that using "grep", too:
egrep -v "^$" file.txt
My bash-specific answer is to recommend using perl substitution operator with the global pattern g flag for this, as follows:
$ perl -pe s'/^\n|^[\ ]*\n//g' $file
xxxxxx
yyyyyy
zzzzzz
This answer illustrates accounting for whether or not the empty lines have spaces in them ([\ ]*), as well as using | to separate multiple search terms/fields. Tested on macOS High Sierra and CentOS 6/7.
FYI, the OP's original code sed '/^$/d' $file works just fine in bash Terminal on macOS High Sierra and CentOS 6/7 Linux at a high-performance supercomputing cluster.
If you want to use modern Rust tools, you can consider:
ripgrep:
cat datafile | rg '.' line with spaces is considered non empty
cat datafile | rg '\S' line with spaces is considered empty
rg '\S' datafile line with spaces is considered empty (-N can be added to remove line numbers for on screen display)
sd
cat datafile | sd '^\n' '' line with spaces is considered non empty
cat datafile | sd '^\s*\n' '' line with spaces is considered empty
sd '^\s*\n' '' datafile inplace edit
Using vim editor to remove empty lines
:%s/^$\n//g
For me with FreeBSD 10.1 with sed worked only this solution:
sed -e '/^[ ]*$/d' "testfile"
inside [] there are space and tab symbols.
test file contains:
fffffff next 1 tabline ffffffffffff
ffffffff next 1 Space line ffffffffffff
ffffffff empty 1 lines ffffffffffff
============ EOF =============
NF is the command of awk you can use to delete empty lines in a file
awk NF filename
and by using sed
sed -r "/^\r?$/d"

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