How do I replace foo. with foo_ with sed simply running
sed 's/foo./foo_/g' file.php
doesn't work.
Escape the .:
sed 's/foo\./foo_/g' file.php
Example:
~$ cat test.txt
foo.bar
~$ sed 's/foo\./foo_/g' test.txt
foo_bar
Interestingly, if you want to search for and replace just the dot, you have to put the dot in a character set. Escaping just the dot alone in a sed command for some reason doesn't work. The dot is still expanded to a single character wild card.
bash --version # Ubuntu Lucid (10.04)
GNU bash, version 4.1.5(1)-release (x86_64-pc-linux-gnu)
Replaces all characters with dash:
echo aa.bb.cc | sed s/\./-/g
# --------
Replaces the dots with a dash:
echo aa.bb.cc | sed s/[.]/-/g
# aa-bb-cc
With the addition of leading characters in the search, the escape works.
echo foo. | sed s/foo\./foo_/g # works
# foo_
Putting the dot in a character set of course also works.
echo foo. | sed s/foo[.]/foo_/g # also works
# foo_
Escape the dot with a \
sed 's/foo\./foo_/g' file.php
If you find the combination of / and \ confusing you can use another 'separator' character
sed 's#foo\.#foo_#g
The 2nd character after the s can be anything and sed will use that character as a separator.
You need to escape the dot - an unescaped dot will match any character after foo.
sed 's/foo\./foo_/g'
For myself, sed 's/foo\./foo_/g' is working. But you can also try:
sed -e 's/foo\./foo_/g'
and
sed -e "s/foo\\./foo_/g"
and
sed 's/foo[.]/foo_/g'
Related
I am trying to use sed to insert sed command at the end of each line in a file using -
sed -r 's/$/ | sed -r s\/abc\/xyz\/ /' filename.extension
What I want next is to have single quotes around the inner sed. So that it will look something like-
sed -r 's/$/ | sed -r 's\/abc\/xyz\/' /' filename.extension
I tried escaping the inner single quotes, but no use.
Basically, I want the following lines -
line 1
line 2
line 3
to turn into-
line 1 | sed -r 's/abc/xyz/'
line 2 | sed -r 's/abc/xyz/'
line 3 | sed -r 's/abc/xyz/'
I am unable to get the single quotes, even with the escape characters.
sed -e "s:$: | sed -r 's/abc/xyz/':" yourfile
Your problem is an example of the general case of nesting shell expressions. There are a number of ways to do this.
Use alternate delimiters. That's what I did here.
Assign subexpressions to variables, and then expand them.
Use lots of \ escapes.
Put your subexpression in a file and read it.
Use alternative delimiter in inner sed and double quote in outer sed to simplify your command:
sed "s/$/ | sed -r 's~abc~xyz~'/" file.ext
btw -r is not really needed in inner sed
This might work for you (GNU sed):
sed 's/$/ | sed -r '\''s\/abc\/xyz\/'\''/' file
Use '\'' to end the current single quote, then in the shell use \' to quote a single quote and finally a single quote to start the quoting of the sed command. Use \/ to quote the forward slash in the sed command.
As the substitution command can use any delimiter:
sed 's#$# | sed -r '\''s/abc/xyz/'\''#' file
reduces the amount of quoting and:
sed "s#$# | sed -r 's/abc/xyz/'#" file
reduces it further. However double quoting sed commands (or any utility) can have unwanted side effects i.e. metacharacters can be evaluated by the shell, so it is best to single quote and live with the "hole-like" mechanism '\''.
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
I have some strings in a textfile that look like this:
[img:3gso40ßf]
I want to replace them to look like normal BBCode:
[img]
How can I do that with sed? I tried this one but it doesn't do anything:
sed -i 's/^[img:.*]/[img]/g' file.txt
Escape those square brackets
Square brackets are metacharacters: they have a special meaning in POSIX regular expressions. If you mean [ and ] literally, you need to escape those characters in your regexp:
$ sed -i .bak 's/\[img:.*\]/\[img\]/g' file.txt
Use [^]]* instead of .*
Because * is greedy, .* will capture more than what you want; see Jidder's comment. To fix this, use [^]]*, which captures a sequence of characters up to (but excluding) the first ] encountered.
$ sed -i .bak 's/\[img:.[^]]\]/\[img\]/g' file.txt
Are you using an incorrect sed -i syntax?
(Thanks to j.a. for his comment.)
Depending on the flavour of sed that you're using, you may be allowed to use sed -i without specifying any <extension> argument, as in
$ sed -i 's/foo/bar/' file.txt
However, in other versions of sed, such as the one that ships with Mac OS X, sed -i expects a mandatory <extension> argument, as in
$ sed -i .bak 's/foo/bar/' file.txt
If you omit that extension argument (.bak, here), you'll get a syntax error. You should check out your sed's man page to figure out whether that argument is optional or mandatory.
Match a specific number of characters
Is there a way to tell sed that there are always 8 random characters after the colon?
Yes, there is. If the number of characters between the colon and the closing square bracket is always the same (8, here), you can make your command more specific:
$ sed -i .bak 's/\[img:[^]]\{8\}\]/\[img\]/g' file.txt
Example
# create some content in file.txt
$ printf "[img:3gso40ßf]\nfoo [img:4t5457th]\n" > file.txt
# inspect the file
$ cat file.txt
[img:3gso40ßf]
foo [img:4t5457th]
# carry out the substitutions
$ sed -i .bak 's/\[img:[^]]\{8\}\]/\[img\]/g' file.txt
# inspect the file again and make sure everything went smoothly
$ cat file.txt
[img]
foo [img]
# if you're happy, delete the backup that sed created
$ rm file.txt.bak
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/'
How i can delete whitespace in each line of file, using bash
For instance, file1.txt. Before:
gg g
gg g
t ttt
after:
gg g
gg g
t ttt
sed -i 's/ //g' your_file will do it, modifying the file inplace.
To delete only the whitespaces at the beginning of one single line, use sed -i 's/^ *//' your_file
In the first expression, we replace all spaces with nothing.
In the second one, we replace at the beginning using the ^ keyword
tr(delete all whitespaces):
$ tr -d ' ' <input.txt >output.txt
$ mv output.txt input.txt
sed(delete leading whitespaces)
$ sed -i 's/^ *//' input.txt
use can use perl -i for in place replacement.
perl -p -e 's/^ *//' file
To delete the white spaces before start of the line if the pattern matches. Use the following command.
For example your foo.in has pattern like this
This is a test
Lolll
blaahhh
This is a testtt
After issuing following command
sed -e '/This/s/ *//' < foo.in > foo.out
The foo.out will be
This is a test
Lolll
blaahhh
This is a testtt
"Whitespace" can include both spaces AND tabs. The solutions presented to date will only match and operate successfully on spaces; they will fail if the whitespace takes the form of a tab.
The below has been tested on the OP's specimen data set with both spaces AND tabs, matching successfully & operating on both:
sed 's/^[[:blank:]]*//g' yourFile
After testing, supply the -i switch to sed to make the changes persistent-