I've got a bunch of files that have sentences ending like this: \#.Next sentence. I'd like to insert a space after the period.
Not all occurrences of \#. do not have a space, however, so my regex checks if the next character after the period is a capital letter.
Because I'm checking one character after the period, I can't just do a replace on \#. to \#., and because I don't know what character is following the period, I'm stuck.
My command currently:
sed -i .bak -E 's/\\#\.[A-Z]/<SOMETHING IN HERE>/g' *.tex
How can I grab the last letter of the matching string to use in the replacement regex?
EDIT: For the record, I'm using a BSD version of sed (I'm using OS X) - from my previous question regarding sed, apparently BSD sed (or at least, the Apple version) doesn't always play nice with GNU sed regular expressions.
The right command should be this:
sed -i.bak -E "s/\\\#.(\S)/\\\#. \1/g" *.tex
Whith it, you match any \# followed by non whitespace (\S) and insert a whitespace (what is made by replacing the whole match with '\# ' plus the the non whitespace just found).
Use this sed command:
sed -i.bak -E 's/(\\#\.)([A-Z])/\1 \2/g' *.tex
OR better:
sed -i.bak -E 's/(\\#\.)([^ \t])/\1 \2/g' *.tex
which will insert space if \#. is not followed by any white-space character (not just capital letter).
This might work for you:
sed -i .bak -E 's/\\#\. \?/\\#. /g' *.tex
Explanation:
If there's a space there replace it with a space, otherwise insert a space.
I think the following would be correct:
s/\\#\.[^\s]/\\#. /g
Only replace the expression if it is not followed by a space.
Related
I need to replace only single instance of backslash.
Input: \\apple\\\orange\banana\\\\grape\\\\\
Output: \\apple\\\orangebanana\\\\grape\\\\\
Tried using sed 's/\\//g' which is replacing all backslashes
Note: The previous character to single backslash can be anything including alphanumeric or special characters. And it's a multiline text file.
Appreciate your help on this.
If you want to consider perl then lookahead and lookahead is exactly what you need here:
perl -pe 's~(?<!\\)\\(?!\\)~~g' file
\\apple\\\orangebanana\\\\grape\\\\\
Details
(?<!\\): Negative lookbehind to make sure that previous char is not \
\\: Match a \
(?!\\): Negative lookahead to make sure that next char is not \
If you want to use sed only then I suggest:
sed -E -e ':a' -e 's~(^|[^\\])\\([^\\]|$)~\1\2~g; ta' g
When you want to replace at most one single backslash, you can use
sed -r 's/(.*[^\]|^)\\([^\].*|$)/\1\2/g'
The command is ugly due to the possibility of a line starting or ending with a backslash (need to include the possibility ^ and $).
When you want to get rid off '\al\l \\sin\gle\slas\hes \\\on \\\\a \\\\\l\i\n\e\' , you can remove a backslash from any sequence of backslashes and afterwards put one back at any place where at least one backslash is left:
sed -r 's/\\([\]*)/\1/g;s/([\]+)/\\\1/g'
or, as suggested by #potong,
sed -E 's/\\(\\*)/\1/g;s/(\\+)/\\&/g'
I like the solution, as it mimics someone who removes one of any sequence of backslashes and tries to undo his last operation. The "bug" in his attempt is that the resulting output is missing the single slashes.
With your shown samples, please try following sed code. Written and tested with GNU sed.
sed -E 's/^(\\\\[^\]*\\\\\\)([^\]*)\\(.*)/\1\2\3/' Input_file
Explanation: Using -E option to enable ERE(extended regular expression) for this program. Then using sed's back reference capability(to save matched part into temp buffer which could be used later in substitution part) here. Creating 1st capturing group which has \\apple\\\ in it. In 2nd capturing group it has orange in it then in 3rd capturing group it has rest of line in it. Now if you see carefully we have left \ between orange and banana, which is needed as per OP's required output.
This might work for you (GNU sed):
sed 's/\>\\\<//g' file
Delete a single \ between word boundaries.
I have a text file with the following pattern written to it:
TIME[32.468ms] -(3)-............."TEXT I WANT TO KEEP"
I would like to discard the first part of each line containing
TIME[32.468ms] -(3)-.............
To test the regular expression I've tried the following:
cat myfile.txt | egrep "^TIME\[.*\]\s\s\-\(3\)\-\.+"
This identifies correctly the lines I want. Now, to delete the pattern I've tried:
cat myfile.txt | sed s/"^TIME\[.*\]\s\s\-\(3\)\-\.+"//
but it just seems to be doing the cat, since it shows the content of the complete file and no substitution happens.
What am I doing wrong?
OS: CentOS 7
With your shown samples, please try following grep command. Written and tested with GNU grep.
grep -oP '^TIME\[\d+\.\d+ms\]\s+-\(\d+\)-\.+\K.*' Input_file
Explanation: Adding detailed explanation for above code.
^TIME\[ ##Matching string TIME from starting of value here.
\d+\.\d+ms\] ##Matching digits(1 or more occurrences) followed by dot digits(1 or more occurrences) followed by ms ] here.
\s+-\(\d+\)-\.+ ##Matching spaces91 or more occurrences) followed by - digits(1 or more occurrences) - and 1 or more dots.
\K ##Using \K option of GNU grep to make sure previous match is found in line but don't consider it in printing, print next matched regex part only.
.* ##to match till end of the value.
2nd solution: Adding awk program here.
awk 'match($0,/^TIME\[[0-9]+\.[0-9]+ms\][[:space:]]+-\([0-9]+\)-\.+/){print substr($0,RSTART+RLENGTH)}' Input_file
Explanation: using match function of awk, to match regex ^TIME\[[0-9]+\.[0-9]+ms\][[:space:]]+-\([0-9]+\)-\.+ which will catch text which we actually want to remove from lines. Then printing rest of the text apart from matched one which is actually required by OP.
This awk using its sub() function:
awk 'sub(/^TIME[[][^]]*].*\.+/,"")' file
"TEXT I WANT TO KEEP"
If there is replacement, sub() returns true.
$ cut -d'"' -f2 file
TEXT I WANT TO KEEP
You may use:
s='TIME[32.468ms] -(3)-............."TEXT I WANT TO KEEP"'
sed -E 's/^TIME\[[^]]*].*\.+//'
"TEXT I WANT TO KEEP"
The \s regex extension may not be supported by your sed.
In BRE syntax (which is what sed speaks out of the box) you do not backslash round parentheses - doing that turns them into regex metacharacters which do not match themselves, somewhat unintuitively. Also, + is just a regular character in BRE, not a repetition operator (though you can turn it into one by similarly backslashing it: \+).
You can try adding an -E option to switch from BRE syntax to the perhaps more familiar ERE syntax, but that still won't enable Perl regex extensions, which are not part of ERE syntax, either.
sed 's/^TIME\[[^][]*\][[:space:]][[:space:]]-(3)-\.*//' myfile.txt
should work on any reasonably POSIX sed. (Notice also how the minus character does not need to be backslash-escaped, though doing so is harmless per se. Furthermore, I tightened up the regex for the square brackets, to prevent the "match anything" regex you had .* from "escaping" past the closing square bracket. In some more detail, [^][] is a negated character class which matches any character which isn't (a newline or) ] or [; they have to be specified exactly in this order to avoid ambiguity in the character class definition. Finally, notice also how the entire sed script should normally be quoted in single quotes, unless you have specific reasons to use different quoting.)
If you have sed -E or sed -r you can use + instead of * but then this complicates the overall regex, so I won't suggest that here.
A simpler one for sed:
sed 's/^[^"]*//' myfile.txt
If the "text you want to keep" always surrounded by the quote like this and only them having the quote in the line starting with "TIME...", then:
sed -n '/^TIME/p' file | awk -F'"' '{print $2}'
should get the line starting with "TIME..." and print the text within the quotes.
Thanks all, for your help.
By the end, I've found a way to make it work:
echo 'TIME[32.468ms] -(3)-.............TEXT I WANT TO KEEP' | grep TIME | sed -r 's/^TIME\[[0-9]+\.[0-9]+ms\]\s\s-\(3\)-\.+//'
More generally,
grep TIME myfile.txt | sed -r ‘s/^TIME\[[0-9]+\.[0-9]+ms\]\s\s-\(3\)-\.+//’
Cheers,
Pedro
so I have a text file with multiple instances looking like this:
word. word or words [something:'else]
I need to replace with a new line the double space after every period followed by a sequence of words and then a "[", like so:
word.\nword or words [something:'else]
I thought about using the sed command in bash with extended regex syntax, but nothing has worked so far... I've tried different variations of this:
sed -E 's/(\.)( )(.*)(.\[)/\1\n\3\4/g' old.txt > new.txt
I'm an absolute beginner at this, so I'm not sure at all about what I'm doing 😳
This might work for you (GNU sed):
sed -E 's/\. ((\w+ )+\[)/\.\n\1/g' file
Replace globally a period followed by two spaces and one or more words space separated followed by an opening square bracket by; a period followed by a newline followed by the matching back reference from the regexp.
Your sed command is almost correct (but contains some redundancies)
sed -E 's/(\.)( )(.*)(.\[)/\1\n\3\4/' old.txt > new.txt
# ^
# You forget terminating the s command
But you don't need to capture everything. A simpler one could be
sed -E 's/\. (.*\[)/.\n\1/' old.txt > new.txt
I don't know much about sed, nor regex. I want to replace every line that contains only tabs by the string '0'. There are also lines in my file that contain only '\n'.
Basically I want to use the regular expression ^\h+$ and replace the matches with 0.
I tried:
sed -i 's/^\h+$/0/' file.txt
But it doesn't work
You can use:
sed -i.bak -E 's/^[[:blank:]]+$/0/' file
POSIX character class [[:blank:]] matches a space or tab which is same as \h in PCRE.
-i.bak is to keep original file in file.bak, in case you want to restore.
In sed the tabulator is called \t. One-or-more need a backslash \+:
sed -i -e 's/^\t\+$/0/' file.txt
I am trying to vocab list for a Greek text we are translating in class. I want to replace every space or tab character with a paragraph mark so that every word appears on its own line. Can anyone give me the sed command, and explain what it is that I'm doing? I’m still trying to figure sed out.
For reasonably modern versions of sed, edit the standard input to yield the standard output with
$ echo 'τέχνη βιβλίο γη κήπος' | sed -E -e 's/[[:blank:]]+/\n/g'
τέχνη
βιβλίο
γη
κήπος
If your vocabulary words are in files named lesson1 and lesson2, redirect sed’s standard output to the file all-vocab with
sed -E -e 's/[[:blank:]]+/\n/g' lesson1 lesson2 > all-vocab
What it means:
The character class [[:blank:]] matches either a single space character or
a single tab character.
Use [[:space:]] instead to match any single whitespace character (commonly space, tab, newline, carriage return, form-feed, and vertical tab).
The + quantifier means match one or more of the previous pattern.
So [[:blank:]]+ is a sequence of one or more characters that are all space or tab.
The \n in the replacement is the newline that you want.
The /g modifier on the end means perform the substitution as many times as possible rather than just once.
The -E option tells sed to use POSIX extended regex syntax and in particular for this case the + quantifier. Without -E, your sed command becomes sed -e 's/[[:blank:]]\+/\n/g'. (Note the use of \+ rather than simple +.)
Perl Compatible Regexes
For those familiar with Perl-compatible regexes and a PCRE-capable sed, use \s+ to match runs of at least one whitespace character, as in
sed -E -e 's/\s+/\n/g' old > new
or
sed -e 's/\s\+/\n/g' old > new
These commands read input from the file old and write the result to a file named new in the current directory.
Maximum portability, maximum cruftiness
Going back to almost any version of sed since Version 7 Unix, the command invocation is a bit more baroque.
$ echo 'τέχνη βιβλίο γη κήπος' | sed -e 's/[ \t][ \t]*/\
/g'
τέχνη
βιβλίο
γη
κήπος
Notes:
Here we do not even assume the existence of the humble + quantifier and simulate it with a single space-or-tab ([ \t]) followed by zero or more of them ([ \t]*).
Similarly, assuming sed does not understand \n for newline, we have to include it on the command line verbatim.
The \ and the end of the first line of the command is a continuation marker that escapes the immediately following newline, and the remainder of the command is on the next line.
Note: There must be no whitespace preceding the escaped newline. That is, the end of the first line must be exactly backslash followed by end-of-line.
This error prone process helps one appreciate why the world moved to visible characters, and you will want to exercise some care in trying out the command with copy-and-paste.
Note on backslashes and quoting
The commands above all used single quotes ('') rather than double quotes (""). Consider:
$ echo '\\\\' "\\\\"
\\\\ \\
That is, the shell applies different escaping rules to single-quoted strings as compared with double-quoted strings. You typically want to protect all the backslashes common in regexes with single quotes.
The portable way to do this is:
sed -e 's/[ \t][ \t]*/\
/g'
That's an actual newline between the backslash and the slash-g. Many sed implementations don't know about \n, so you need a literal newline. The backslash before the newline prevents sed from getting upset about the newline. (in sed scripts the commands are normally terminated by newlines)
With GNU sed you can use \n in the substitution, and \s in the regex:
sed -e 's/\s\s*/\n/g'
GNU sed also supports "extended" regular expressions (that's egrep style, not perl-style) if you give it the -r flag, so then you can use +:
sed -r -e 's/\s+/\n/g'
If this is for Linux only, you can probably go with the GNU command, but if you want this to work on systems with a non-GNU sed (eg: BSD, Mac OS-X), you might want to go with the more portable option.
All of the examples listed above for sed break on one platform or another. None of them work with the version of sed shipped on Macs.
However, Perl's regex works the same on any machine with Perl installed:
perl -pe 's/\s+/\n/g' file.txt
If you want to save the output:
perl -pe 's/\s+/\n/g' file.txt > newfile.txt
If you want only unique occurrences of words:
perl -pe 's/\s+/\n/g' file.txt | sort -u > newfile.txt
option 1
echo $(cat testfile)
Option 2
tr ' ' '\n' < testfile
This should do the work:
sed -e 's/[ \t]+/\n/g'
[ \t] means a space OR an tab. If you want any kind of space, you could also use \s.
[ \t]+ means as many spaces OR tabs as you want (but at least one)
s/x/y/ means replace the pattern x by y (here \n is a new line)
The g at the end means that you have to repeat as many times it occurs in every line.
You could use POSIX [[:blank:]] to match a horizontal white-space character.
sed 's/[[:blank:]]\+/\n/g' file
or you may use [[:space:]] instead of [[:blank:]] also.
Example:
$ echo 'this is a sentence' | sed 's/[[:blank:]]\+/\n/g'
this
is
a
sentence
You can also do it with xargs:
cat old | xargs -n1 > new
or
xargs -n1 < old > new
Using gawk:
gawk '{$1=$1}1' OFS="\n" file