I need to delete from a file all the words that do not contain any uppercase in bash.
I use the sed command but the output is the same as the input:
I tried sed 's/[^0-9]*//' file
Example input:
sjasd
ksaLK
asdn
Asdw
Output
ksaLK
Asdw
Could you please try following.
sed -n '/[A-Z]/p' Input_file
As per #PaulHodges's comment, once you are happy with results use sed -i .... option in above code to make changes in Input_file itself.
To make a file without those:
grep '[A-Z]' infile > outfile
This is a nondestructive way to check first. Then you could replace the old file with the new one.
If you really want to edit the existing file in place:
sed -i '/[A-Z]/!d' infile
This says to delete all lines that do not have a capital letter.
Related
I have a file, which has multiple lines.
For example:
a
ab#
ad.
a12fs
b
c
...
I want to use sed or awk delete the line, if the line include symbols or numbers. (For example, I want to delete: ab#, ad., a12fs.... lines)
or in another words, I just want to keep the line which include [a-z][A-Z] .
I know how to delete number line,
sed '/[0-9]/d' file.txt
but I do not know how to delete symbols lines.
Or there has any easy way to do that?
To keep blank lines:
grep '^[[:alpha:]]*$' file
sed '/[^[:alpha:]]/d' file
awk '/^[[:alpha:]]*$/' file
To remove blank lines:
grep '^[[:alpha:]]+$' file
sed -E -n '/^[[:alpha:]]+$/p' file
awk '/^[[:alpha:]]+$/' file
grep works well too and is even simpler: just do the reverse: keep the lines that interest you, which are way easier to define
grep -i '^[a-z]*$' file.txt
(match lines containing only letters and empty lines, and -i option makes grep case-insensitive)
to remove empty lines as well:
grep -i '^[a-z]+$' file.txt
caution when using Windows text files, as there's a carriage return at the end of the line, so nothing would match depending on grep versions (tested on windows here and it works)
but just in case:
grep -iP '^[a-z]*\r?$'
(note the P option to enable perl expressions or \r is not recognized)
You can use this sed:
sed '/^[A-Za-z0-9]\+$/!d' file
(OR)
sed '/[^A-Za-z0-9]/d' file
$ awk '!/[^[:alpha:]]/' file.txt
a
b
c
i am trying to remove some text from a file, i need to find the line number using a string and then remove from that line to the end of the file.
i tried using sed and outputting to a new file using a string as a search term but it does not keep the lines, it just prints the whole file on one line, which isnt helpful as the rest of the script relies on line numbers.
my code so far is:
file=$(sed -ie '/<div class="col-wrapper">/,$d' < file1.txt)
echo $file > file.txt
You can just use inline editing in sed:
sed -i '/<div class="col-wrapper">/,$d' file1.txt
to save changes to file1.txt
This might work for you (GNU sed):
sed -i '/<div class="col-wrapper">/Q' file1.txt
My text file contains 100 lines and the text file surely contains Technology and /Technology words .In which ,I want to remove Technology and /Technology words present in the file using shell scripting.
sed -i.bak -e 's#/Technology##g' -e 's#Technology##g' my_text_file
This is delete the words and also make a backup of the original file just in case
sed -i -e 's#/Technology##g' -e 's#Technology##g' my_text_file
This will not make a backup but just modify the original file
You can try this one.
sed -r 's/<[\/]*technology>//g' a
Here is an awk
cat file
This Technology
More here
Mine /Technology must go
awk '{gsub(/\/*Technology/,"")}1' file
This
More here
Mine must go
By adding an extra space in the regex, it will not leave an extra space in the output.
awk '{gsub(/\/*Technology /,"")}1' file
This Technology
More here
Mine must go
To write back to original file
awk '{gsub(/\/*Technology /,"")}1' file > tmp && mv tmp file
If you have gnu awk 4.1+ you can do
awk -i '{gsub(/\/*Technology /,"")}1' file
Suppose my file a.conf is as following
Include /1
Include /2
Include /3
I want to replace "Include /2" with a new line, I write the code in .sh file :
line="Include /2"
rep=""
sed -e "s/${line}/${rep}/g" /root/new_scripts/a.conf
But after running the sh file, It give me the following error
sed: -e expression #1, char 14: unknown option to `s'
If you are using a newer version of sed you can use -i to read from and write to the same file. Using -i you can specify a file extension so a backup will be made, incase something went wrong. Also you don't need to use the -e flag unless you are using multiple commands
sed -i.bak "s/${line}/${rep}/g" /root/new_scripts/a.conf
I have just noticed that as the variables you are using are quoted strings you may want to use single quotes around your sed expression. Also your string contains a forward slash, to avoid any errors you can use a different delimiter in your sed command (the delimiter doesn't need to be a slash):
sed -i.bak 's|${line}|${rep}|g' /root/new_scripts/a.conf
You have to write the changes to a new file and then, move the new file over the old one. Like this:
line="Include 2"
rep=""
sed -e "s/${line}/${rep}/g" /root/new_scripts/a.conf > /root/new_scripts/a.conf-new
mv /root/new_scripts/a.conf-new /root/new_scripts/a.conf
The redirection (> /root/new_scripts/a.conf) wipes the contents of the file before sed can see it.
You need to pass the -i option to sed to edit the file in-place:
sed -i "s/${line}/${rep}/g" /root/new_scripts/a.conf
You can also ask sed to create a backup of the original file:
sed -i.bak "s/${line}/${rep}/g" /root/new_scripts/a.conf
So, if you have to replace a substring in a file, you can use sed command like this, say we have a file as file.txt, so replacing a substring in it can be done like this
searchString="abc";
replaceString="def";
sed -i '' "s|$searchString|$replaceString|g" file.txt
This will all the occurrences of "abc" with "def" in file.txt. Also, this keeps a check for any / character present in the variables used, and with no backup file made.
All of the lines with comments in a file begin with #. How can I delete all of the lines (and only those lines) which begin with #? Other lines containing #, but not at the beginning of the line should be ignored.
This can be done with a sed one-liner:
sed '/^#/d'
This says, "find all lines that start with # and delete them, leaving everything else."
I'm a little surprised nobody has suggested the most obvious solution:
grep -v '^#' filename
This solves the problem as stated.
But note that a common convention is for everything from a # to the end of a line to be treated as a comment:
sed 's/#.*$//' filename
though that treats, for example, a # character within a string literal as the beginning of a comment (which may or may not be relevant for your case) (and it leaves empty lines).
A line starting with arbitrary whitespace followed by # might also be treated as a comment:
grep -v '^ *#' filename
if whitespace is only spaces, or
grep -v '^[ ]#' filename
where the two spaces are actually a space followed by a literal tab character (type "control-v tab").
For all these commands, omit the filename argument to read from standard input (e.g., as part of a pipe).
The opposite of Raymond's solution:
sed -n '/^#/!p'
"don't print anything, except for lines that DON'T start with #"
you can directly edit your file with
sed -i '/^#/ d'
If you want also delete comment lines that start with some whitespace use
sed -i '/^\s*#/ d'
Usually, you want to keep the first line of your script, if it is a sha-bang, so sed should not delete lines starting with #!. also it should delete lines, that just contain only a hash but no text. put it all together:
sed -i '/^\s*\(#[^!].*\|#$\)/d'
To be conform with all sed variants you need to add a backup extension to the -i option:
sed -i.bak '/^\s*#/ d' $file
rm -Rf $file.bak
You can use the following for an awk solution -
awk '/^#/ {sub(/#.*/,"");getline;}1' inputfile
This answer builds upon the earlier answer by Keith.
egrep -v "^[[:blank:]]*#" should filter out comment lines.
egrep -v "^[[:blank:]]*(#|$)" should filter out both comments and empty lines, as is frequently useful.
For information about [:blank:] and other character classes, refer to https://en.wikipedia.org/wiki/Regular_expression#Character_classes.
If you want to delete from the file starting with a specific word, then do this:
grep -v '^pattern' currentFileName > newFileName && mv newFileName currentFileName
So we have removed all the lines starting with a pattern, writing the content into a new file, and then copy the content back into the source/current file.
You also might want to remove empty lines as well
sed -E '/(^$|^#)/d' inputfile
Delete all empty lines and also all lines starting with a # after any spaces:
sed -E '/^$|^\s*#/d' inputfile
For example, see the following 3 deleted lines (including just line numbers!):
1. # first comment
2.
3. # second comment
After testing the command above, you can use option -i to edit the input file in place.
Just this!
Here is it with a loop for all files with some extension:
ll -ltr *.filename_extension > list.lst
for i in $(cat list.lst | awk '{ print $8 }') # validate if it is the 8 column on ls
do
echo $i
sed -i '/^#/d' $i
done