I was working on a program that could transfer files using sftp program:
sftp -oBatchMode=no -b ${BATCH_FILE} user#$123.123.123.123:/home << EOF
bye
EOF
One of my requirement is I must have a BATCH_FILE use with sftp and the batch file was generate using following script:
files=$(ls -1 ${SRC_PATH}/*.txt)
echo "$files" > ${TEMP_FILE}
while read file
do
if [ -s "${file}" ]
then
echo ${file} >> "${PARSE_FILE}" ## line 1
fi
done < ${TEMP_FILE}
awk '$0="put "$0' ${PARSE_FILE} > ${BATCH_FILE}
Somehow my program doesn't able to handle files with space in it. I did try using following code to replace line 1 but failed, the output of this will show filename\.txt.
newfile=`echo $file | tr ' ' '\\ '`
echo ${newfile} >> "${PARSE_FILE}"
In order to handle file name with space, how could I append a \ in front of the space within a file name?
THE PROBLEM
The problem is that tr SET1 SET2 will replace the Nth character in SET1 with the Nth character in SET2, which means that you are effectively replacing every space by \, instead of adding a backslash before every space.
PROPOSED SOLUTION
Instead of manually trying to fix the missing spaces, upon using your variable that might contain spaces; wrap it in quotes and let the shell handle the trouble for you.
See the below example:
$ echo $FILENAME
file with spaces.txt
$ ls $FILENAME
ls: cannot access file: No such file or directory
ls: cannot access with: No such file or directory
ls: cannot access spaces.txt: No such file or directory
$ ls "$FILENAME"
file with spaces.txt
But I really wanna replace stuff..
Well, if you really want a command to change every ' ' (space) into '\ ' (backslash, space) you could use sed with a basic replace-pattern, as the below:
$ echo "file with spaces.txt" | sed 's, ,\\ ,g'
file\ with\ spaces.txt
I haven't looked too closely at what you're trying to do there, but I do know that bash can handle filenames with spaces in them if you double-quote them. Why not try quoting every filename variable and see if that works? You're quoting some of them but not all yet.
Like try these: "${newfile}" or just "$newfile" "$file" "$tempfile" etc...
You can further simplify your code if you're using Bash:
function generate_batch_file {
for FILE in "${SRC_PATH}"/*.txt; do
[[ -s $FILE ]] && echo "put {$FILE// /\\ }"
done
}
sftp -oBatchMode=no -b <(generate_batch_file) user#$123.123.123.123:/home <<< "bye"
you can try to rename the file to work and rename it again after it has done.
I need to add the following line to the end of a config file:
include "/configs/projectname.conf"
to a file called lighttpd.conf
I am looking into using sed to do this, but I can't work out how.
How would I only insert it if the line doesn't already exist?
Just keep it simple :)
grep + echo should suffice:
grep -qxF 'include "/configs/projectname.conf"' foo.bar || echo 'include "/configs/projectname.conf"' >> foo.bar
-q be quiet
-x match the whole line
-F pattern is a plain string
https://linux.die.net/man/1/grep
Edit:
incorporated #cerin and #thijs-wouters suggestions.
This would be a clean, readable and reusable solution using grep and echo to add a line to a file only if it doesn't already exist:
LINE='include "/configs/projectname.conf"'
FILE='lighttpd.conf'
grep -qF -- "$LINE" "$FILE" || echo "$LINE" >> "$FILE"
If you need to match the whole line use grep -xqF
Add -s to ignore errors when the file does not exist, creating a new file with just that line.
Try this:
grep -q '^option' file && sed -i 's/^option.*/option=value/' file || echo 'option=value' >> file
Using sed, the simplest syntax:
sed \
-e '/^\(option=\).*/{s//\1value/;:a;n;ba;q}' \
-e '$aoption=value' filename
This would replace the parameter if it exists, else would add it to the bottom of the file.
Use the -i option if you want to edit the file in-place.
If you want to accept and keep white spaces, and in addition to remove the comment, if the line already exists, but is commented out, write:
sed -i \
-e '/^#\?\(\s*option\s*=\s*\).*/{s//\1value/;:a;n;ba;q}' \
-e '$aoption=value' filename
Please note that neither option nor value must contain a slash /, or you will have to escape it to \/.
To use bash-variables $option and $value, you could write:
sed -i \
-e '/^#\?\(\s*'${option//\//\\/}'\s*=\s*\).*/{s//\1'${value//\//\\/}'/;:a;n;ba;q}' \
-e '$a'${option//\//\\/}'='${value//\//\\/} filename
The bash expression ${option//\//\\/} quotes slashes, it replaces all / with \/.
Note: Just trapped into a problem. In bash you may quote "${option//\//\\/}", but in the sh of busybox, this does not work, so you should avoid the quotes, at least in non-bourne-shells.
All combined in a bash function:
# call option with parameters: $1=name $2=value $3=file
function option() {
name=${1//\//\\/}
value=${2//\//\\/}
sed -i \
-e '/^#\?\(\s*'"${name}"'\s*=\s*\).*/{s//\1'"${value}"'/;:a;n;ba;q}' \
-e '$a'"${name}"'='"${value}" $3
}
Explanation:
/^\(option=\).*/: Match lines that start with option= and (.*) ignore everything after the =. The \(…\) encloses the part we will reuse as \1later.
/^#?(\s*'"${option//////}"'\s*=\s*).*/: Ignore commented out code with # at the begin of line. \? means «optional». The comment will be removed, because it is outside of the copied part in \(…\). \s* means «any number of white spaces» (space, tabulator). White spaces are copied, since they are within \(…\), so you do not lose formatting.
/^\(option=\).*/{…}: If matches a line /…/, then execute the next command. Command to execute is not a single command, but a block {…}.
s//…/: Search and replace. Since the search term is empty //, it applies to the last match, which was /^\(option=\).*/.
s//\1value/: Replace the last match with everything in (…), referenced by \1and the textvalue`
:a;n;ba;q: Set label a, then read next line n, then branch b (or goto) back to label a, that means: read all lines up to the end of file, so after the first match, just fetch all following lines without further processing. Then q quit and therefore ignore everything else.
$aoption=value: At the end of file $, append a the text option=value
More information on sed and a command overview is on my blog:
https://marc.wäckerlin.ch/computer/stream-editor-sed-overview-and-reference
If writing to a protected file, #drAlberT and #rubo77 's answers might not work for you since one can't sudo >>. A similarly simple solution, then, would be to use tee --append (or, on MacOS, tee -a):
LINE='include "/configs/projectname.conf"'
FILE=lighttpd.conf
grep -qF "$LINE" "$FILE" || echo "$LINE" | sudo tee --append "$FILE"
Here's a sed version:
sed -e '\|include "/configs/projectname.conf"|h; ${x;s/incl//;{g;t};a\' -e 'include "/configs/projectname.conf"' -e '}' file
If your string is in a variable:
string='include "/configs/projectname.conf"'
sed -e "\|$string|h; \${x;s|$string||;{g;t};a\\" -e "$string" -e "}" file
If, one day, someone else have to deal with this code as "legacy code", then that person will be grateful if you write a less exoteric code, such as
grep -q -F 'include "/configs/projectname.conf"' lighttpd.conf
if [ $? -ne 0 ]; then
echo 'include "/configs/projectname.conf"' >> lighttpd.conf
fi
another sed solution is to always append it on the last line and delete a pre existing one.
sed -e '$a\' -e '<your-entry>' -e "/<your-entry-properly-escaped>/d"
"properly-escaped" means to put a regex that matches your entry, i.e. to escape all regex controls from your actual entry, i.e. to put a backslash in front of ^$/*?+().
this might fail on the last line of your file or if there's no dangling newline, I'm not sure, but that could be dealt with by some nifty branching...
Here is a one-liner sed which does the job inline. Note that it preserves the location of the variable and its indentation in the file when it exists. This is often important for the context, like when there are comments around or when the variable is in an indented block. Any solution based on "delete-then-append" paradigm fails badly at this.
sed -i '/^[ \t]*option=/{h;s/=.*/=value/};${x;/^$/{s//option=value/;H};x}' test.conf
With a generic pair of variable/value you can write it this way:
var=c
val='12 34' # it handles spaces nicely btw
sed -i '/^[ \t]*'"$var"'=/{h;s/=.*/='"$val"'/};${x;/^$/{s//c='"$val"'/;H};x}' test.conf
Finally, if you want also to keep inline comments, you can do it with a catch group. E.g. if test.conf contains the following:
a=123
# Here is "c":
c=999 # with its own comment and indent
b=234
d=567
Then running this
var='c'
val='"yay"'
sed -i '/^[ \t]*'"$var"'=/{h;s/=[^#]*\(.*\)/='"$val"'\1/;s/'"$val"'#/'"$val"' #/};${x;/^$/{s//'"$var"'='"$val"'/;H};x}' test.conf
Produces that:
a=123
# Here is "c":
c="yay" # with its own comment and indent
b=234
d=567
As an awk-only one-liner:
awk -v s=option=value '/^option=/{$0=s;f=1} {a[++n]=$0} END{if(!f)a[++n]=s;for(i=1;i<=n;i++)print a[i]>ARGV[1]}' file
ARGV[1] is your input file. It is opened and written to in the for loop of theEND block. Opening file for output in the END block replaces the need for utilities like sponge or writing to a temporary file and then mving the temporary file to file.
The two assignments to array a[] accumulate all output lines into a. if(!f)a[++n]=s appends the new option=value if the main awk loop couldn't find option in file.
I have added some spaces (not many) for readability, but you really need just one space in the whole awk program, the space after print.
If file includes # comments they will be preserved.
Here's an awk implementation
/^option *=/ {
print "option=value"; # print this instead of the original line
done=1; # set a flag, that the line was found
next # all done for this line
}
{print} # all other lines -> print them
END { # end of file
if(done != 1) # haven't found /option=/ -> add it at the end of output
print "option=value"
}
Run it using
awk -f update.awk < /etc/fdm_monitor.conf > /etc/fdm_monitor.conf.tmp && \
mv /etc/fdm_monitor.conf.tmp /etc/fdm_monitor.conf
or
awk -f update.awk < /etc/fdm_monitor.conf | sponge /etc/fdm_monitor.conf
EDIT:
As a one-liner:
awk '/^option *=/ {print "option=value";d=1;next}{print}END{if(d!=1)print "option=value"}' /etc/fdm_monitor.conf | sponge /etc/fdm_monitor.conf
use awk
awk 'FNR==NR && /configs.*projectname\.conf/{f=1;next}f==0;END{ if(!f) { print "your line"}} ' file file
sed -i 's/^option.*/option=value/g' /etc/fdm_monitor.conf
grep -q "option=value" /etc/fdm_monitor.conf || echo "option=value" >> /etc/fdm_monitor.conf
here is an awk one-liner:
awk -v s="option=value" '/^option/{f=1;$0=s}7;END{if(!f)print s}' file
this doesn't do in-place change on the file, you can however :
awk '...' file > tmpfile && mv tmpfile file
Using sed, you could say:
sed -e '/option=/{s/.*/option=value/;:a;n;:ba;q}' -e 'aoption=value' filename
This would replace the parameter if it exists, else would add it to the bottom of the file.
Use the -i option if you want to edit the file in-place:
sed -i -e '/option=/{s/.*/option=value/;:a;n;:ba;q}' -e 'aoption=value' filename
sed -i '1 h
1 !H
$ {
x
s/^option.*/option=value/g
t
s/$/\
option=value/
}' /etc/fdm_monitor.conf
Load all the file in buffer, at the end, change all occurence and if no change occur, add to the end
The answers using grep are wrong. You need to add an -x option to match the entire line otherwise lines like #text to add will still match when looking to add exactly text to add.
So the correct solution is something like:
grep -qxF 'include "/configs/projectname.conf"' foo.bar || echo 'include "/configs/projectname.conf"' >> foo.bar
Using sed: It will insert at the end of line. You can also pass in variables as usual of course.
grep -qxF "port=9033" $light.conf
if [ $? -ne 0 ]; then
sed -i "$ a port=9033" $light.conf
else
echo "port=9033 already added"
fi
Using oneliner sed
grep -qxF "port=9033" $lightconf || sed -i "$ a port=9033" $lightconf
Using echo may not work under root, but will work like this. But it will not let you automate things if you are looking to do it since it might ask for password.
I had a problem when I was trying to edit from the root for a particular user. Just adding the $username before was a fix for me.
grep -qxF "port=9033" light.conf
if [ $? -ne 0 ]; then
sudo -u $user_name echo "port=9033" >> light.conf
else
echo "already there"
fi
I elaborated on kev's grep/sed solution by setting variables in order to reduce duplication.
Set the variables in the first line (hint: $_option shall match everything on the line up until the value [including any seperator like = or :]).
_file="/etc/ssmtp/ssmtp.conf" _option="mailhub=" _value="my.domain.tld" \
sh -c '\
grep -q "^$_option" "$_file" \
&& sed -i "s/^$_option.*/$_option$_value/" "$_file" \
|| echo "$_option$_value" >> "$_file"\
'
Mind that the sh -c '...' just has the effect of widening the scope of the variables without the need for an export. (See Setting an environment variable before a command in bash not working for second command in a pipe)
You can use this function to find and search config changes:
#!/bin/bash
#Find and Replace config values
find_and_replace_config () {
file=$1
var=$2
new_value=$3
awk -v var="$var" -v new_val="$new_value" 'BEGIN{FS=OFS="="}match($1, "^\\s*" var "\\s*") {$2=" " new_val}1' "$file" > output.tmp && sudo mv output.tmp $file
}
find_and_replace_config /etc/php5/apache2/php.ini max_execution_time 60
If you want to run this command using a python script within a Linux terminal...
import os,sys
LINE = 'include '+ <insert_line_STRING>
FILE = <insert_file_path_STRING>
os.system('grep -qxF $"'+LINE+'" '+FILE+' || echo $"'+LINE+'" >> '+FILE)
The $ and double quotations had me in a jungle, but this worked.
Thanks everyone
Try:
LINE='include "/configs/projectname.conf"'
sed -n "\|$LINE|q;\$a $LINE" lighttpd.conf >> lighttpd.conf
Use the pipe as separator and quit if $LINE has been found. Otherwise, append $LINE at the end.
Since we only read the file in sed command, I suppose we have no clobber issue in general (it depends on your shell settings).
Using only sed I'd suggest the following solution:
sed -i \
-e 's#^include "/configs/projectname.conf"#include "/configs/projectname.conf"#' \
-e t \
-e '$ainclude "/configs/projectname.conf"' lighttpd.conf
s replace the line include "/configs/projectname.conf with itself (using # as delimiter here)
t if the replacement was successful skip the rest of the commands
$a otherwise jump to the last line and append include "/configs/projectname.conf after it
Almost all of the answers work but not in all scenarios or OS as per my experience. Only thing that worked on older systems and new and different flavours of OS is the following.
I needed to append KUBECONFIG path to bashrc file if it doesnt exist. So, what I did is
I assume that it exists and delete it.
with sed I append the string I want.
sed -i '/KUBECONFIG=/d' ~/.bashrc
echo 'export KUBECONFIG=/etc/rancher/rke2/rke2.yaml' >> ~/.bashrc
I needed to edit a file with restricted write permissions so needed sudo. working from ghostdog74's answer and using a temp file:
awk 'FNR==NR && /configs.*projectname\.conf/{f=1;next}f==0;END{ if(!f) { print "your line"}} ' file > /tmp/file
sudo mv /tmp/file file
I have a folder full of text files. I need to append the same block of text to each of them (and of course overwrite the original file).
I was wondering what the correct Bash shell syntax would be for this. Would I use cat?
I have done a few batch scripts but I'm not a Bash expert. Any suggestions appreciated.
Use append redirection.
for f in *.txt
do
cat footer >> "$f"
done
If you're needing to do this via a script, you can use echo and append redirection to get the extra text into the files.
FILES=pathto/*
for f in $FILES ; do
echo "#extra text" >> $f
done
sed -i.bak "$ a $(<file_block_of_text)" *.txt
Variant of kurumi's answer:
sed -i.bak "\$aTEXTTOINSERT" *.txt
For more details, see SED: insert something to the last line?
very simply one which worked well for me
#!/bin/sh
FILES="./files/*"
for f in $FILES
do
echo '0000000' | cat - $f > temp && mv temp $f
done
I am using sed in a script to do a replace and I want to have the replaced file overwrite the file. Normally I think that you would use this:
% sed -i 's/cat/dog/' manipulate
sed: illegal option -- i
However as you can see my sed does not have that command.
I tried this:
% sed 's/cat/dog/' manipulate > manipulate
But this just turns manipulate into an empty file (makes sense).
This works:
% sed 's/cat/dog/' manipulate > tmp; mv tmp manipulate
But I was wondering if there was a standard way to redirect output into the same file that input was taken from.
I commonly use the 3rd way, but with an important change:
$ sed 's/cat/dog/' manipulate > tmp && mv tmp manipulate
I.e. change ; to && so the move only happens if sed is successful; otherwise you'll lose your original file as soon as you make a typo in your sed syntax.
Note! For those reading the title and missing the OP's constraint "my sed doesn't support -i": For most people, sed will support -i, so the best way to do this is:
$ sed -i 's/cat/dog/' manipulate
Yes, -i is also supported in FreeBSD/MacOSX sed, but needs the empty string as an argument to edit a file in-place.
sed -i "" 's/old/new/g' file # FreeBSD sed
If you don't want to move copies around, you could use ed:
ed file.txt <<EOF
%s/cat/dog/
wq
EOF
Kernighan and Pike in The Art of Unix Programming discuss this issue. Their solution is to write a script called overwrite, which allows one to do such things.
The usage is: overwrite file cmd file.
# overwrite: copy standard input to output after EOF
opath=$PATH
PATH=/bin:/usr/bin
case $# in
0|1) echo 'Usage: overwrite file cmd [args]' 1>&2; exit 2
esac
file=$1; shift
new=/tmp/overwr1.$$; old=/tmp/overwr2.$$
trap 'rm -f $new $old; exit 1' 1 2 15 # clean up
if PATH=$opath "$#" >$new
then
cp $file $old # save original
trap '' 1 2 15 # wr are commmitted
cp $new $file
else
echo "overwrite: $1 failed, $file unchanged" 1>&2
exit 1
fi
rm -f $new $old
Once you have the above script in your $PATH, you can do:
overwrite manipulate sed 's/cat/dog/' manipulate
To make your life easier, you can use replace script from the same book:
# replace: replace str1 in files with str2 in place
PATH=/bin:/usr/bin
case $# in
0|2) echo 'Usage: replace str1 str2 files' 1>&2; exit 1
esac
left="$1"; right="$2"; shift; shift
for i
do
overwrite $i sed "s#$left#$right#g" $i
done
Having replace in your $PATH too will allow you to say:
replace cat dog manipulate
You can use sponge from the moreutils.
sed "s/cat/dog/" manipulate | sponge manipulate
Perhaps -i is gnu sed, or just an old version of sed, but anyways. You're on the right track. The first option is probably the most common one, the third option is if you want it to work everywhere (including solaris machines)... :) These are the 'standard' ways of doing it.
To change multiple files (and saving a backup of each as *.bak):
perl -p -i -e "s/oldtext/newtext/g" *
replaces any occurence of oldtext by newtext in all files in the current folder. However you will have to escape all perl special characters within oldtext and newtext using the backslash
This is called a “Perl pie” (mnemonic: easy as a pie)
The -i flag tells it do do in-place replacement, and it should be ok to use single (“'”) as well as double (“””) quotes.
If using ./* instead of just *, you should be able to do it in all sub-directories
See man perlrun for more details, including how to take a backup file of the original.
using sed:
sed -i 's/old/new/g' ./* (used in GNU)
sed -i '' 's/old/new/g' ./* (used in FreeBSD)
-i option is not available in standard sed.
Your alternatives are your third way or perl.
A lot of answers, but none of them is correct. Here is the correct and simplest one:
$ echo "111 222 333" > file.txt
$ sed -i -s s/222/444/ file.txt
$ cat file.txt
111 444 333
$
Workaround using open file handles:
exec 3<manipulate
Prevent open file from being truncated:
rm manipulate
sed 's/cat/dog/' <&3 > manipulate