I need to use sed instead of echo and append to the end of a file: list.txt
list.txt has a list of directories:
/desktop/test1/file1
/desktop/test2/file1
I need to append another directory with slashes to this list.txt at the end of the file if that directory already doesn't exist in the list. Such as: /desktop/file1
The result should be:
/desktop/test1/file1
/desktop/test2/file1
/desktop/file1
I've tried using this script but am running into syntax errors with the a command which I've been seeing could be a mac issue?:
#!/bin/bash
if ! grep -q "/desktop/file1" user/admin/Desktop/list.txt; then
sed -i -e '$a/desktop/file1' user/admin/Desktop/list.txt
fi
The a command is used as a\ in standard sed and should be followed by a newline and the text to be written. The form you use is a GNU extension. So a standard sed command to do the job could be:
sed -i '' '$a\
/desktop/file1' user/admin/Desktop/list.txt
or
sed -i '' '$a\'$'\n''/desktop/file1' user/admin/Desktop/list.txt
using ANSI-C quoting in bash.
Related
I want to append bash variable (which has html tags) at the beginning of a file.
INSERTTO=<h2>title</h2>
<li>sdfdsf</li>
Below is the command I am using -
sed -i '1i'$INSERTTO file.html
But i am getting error -
sed: -e expression #1, char 177: unknown command: `<'
Do i need to encode the html tags in INSERTTO variable ?
First of all, use quotes:
INSERTTO='<h2>title</h2>
<li>sdfdsf</li>'
Then try this:
sed "1 i $INSERTTO" file.html
Start with some text in your file, e.g.
$ cat file
some text
Then you need your variable to contain an explicit '\n' character where the line break is, e.g. INSERTTO='<h2>title</h2>\n<li>sdfdsf</li>'. Then you can use the sed expression to place both lines as the beginning lines in the file, e.g.
$ INSERTTO='<h2>title</h2>\n<li>sdfdsf</li>'; sed "1i $INSERTTO" file
<h2>title</h2>
<li>sdfdsf</li>
some text
Now at present, what will be done has only been written to the terminal stdout. To modify the file in place, you will need to add the -i option for sed (or -i.bak to save a backup of the original file with the .bak extension. (however you prefer to do it)
I offer you an ed(1) solution.
INSERTTO=<h2>title</h2>
<li>sdfdsf</li>
printf '%s\n' 1i "$INSERTTO" . w | ed -s file.html
Assuming the file is not empty that will work. otherwise use 0a as the address and command instead of 1i
... Or use the cat(1) and mv(1)
INSERTTO=<h2>title</h2>
<li>sdfdsf</li>
Add the stdin flag and use a herestring works in bash but not in POSIX shells.
cat - file.html <<< "$INSERTTO"
You should see the output to stdout, redirect it to another file and move that file to the original file, something like this.
cat - file.html <<< "$INSERTTO" > tempfile && mv tempfile file.html
However if the html file is a symlink then it is now broken... a work around would be to use another cat.
cat - file.html <<< "$INSERTTO" > tempfile && cat tempfile > file.html && rm tempfile.
tempfile is just an example you should take a loot at How to create a tempfile in a secure manner
I have these files
NotRequired.txt (having lines which need to be remove)
Need2CleanSED.txt (big file , need to clean)
Need2CleanGRP.txt (big file , need to clean)
content:
more NotRequired.txt
[abc-xyz_pqr-pe2_123]
[lon-abc-tkt_1202]
[wat-7600-1_414]
[indo-pak_isu-5_761]
I am reading above file and want to remove lines from Need2Clean???.txt, trying via SED and GREP but no success.
myFile="NotRequired.txt"
while IFS= read -r HKline
do
sed -i '/$HKline/d' Need2CleanSED.txt
done < "$myFile"
myFile="NotRequired.txt"
while IFS= read -r HKline
do
grep -vE \"$HKline\" Need2CleanGRP.txt > Need2CleanGRP.txt
done < "$myFile"
Looks as if the Variable and characters [] making some problem.
What you're doing is extremely inefficient and error prone. Just do this:
grep -vF -f NotRequired.txt Need2CleanGRP.txt > tmp &&
mv tmp Need2CleanGRP.txt
Thanks to grep -F the above treats each line of NotRequired.txt as a string rather than a regexp so you don't have to worry about escaping RE metachars like [ and you don't need to wrap it in a shell loop - that one command will remove all undesirable lines in one execution of grep.
Never do command file > file btw as the shell might decide to execute the > file first and so empty file before command gets a chance to read it! Always do command file > tmp && mv tmp file instead.
Your assumption is correct. The [...] construct looks for any characters in that set, so you have to preface ("escape") them with \. The easiest way is to do that in your original file:
sed -i -e 's:\[:\\[:' -e 's:\]:\\]:' "${myFile}"
If you don't like that, you can probably put the sed command in where you're directing the file in:
done < replace.txt|sed -e 's:\[:\\[:' -e 's:\]:\\]:'
Finally, you can use sed on each HKline variable:
HKline=$( echo $HKline | sed -e 's:\[:\\[:' -e 's:\]:\\]:' )
try gnu sed:
sed -Ez 's/\n/\|/g;s!\[!\\[!g;s!\]!\\]!g; s!(.*).!/\1/d!' NotRequired.txt| sed -Ef - Need2CleanSED.txt
Two sed process are chained into one by shell pipe
NotRequired.txt is 'slurped' by sed -z all at once and substituted its \n and [ meta-char with | and \[ respectively of which the 2nd process uses it as regex script for the input file, ie. Need2CleanSED.txt. 1st process output;
/\[abc-xyz_pqr-pe2_123\]|\[lon-abc-tkt_1202\]|\[wat-7600-1_414\]|\[indo-pak_isu-5_761\]/d
add -u ie. unbuffered, option to evade from batch process, sort of direct i/o
I've writted a sed script to replace all ^^ with NULL. It seems though that sed is only catching a pair, but not including the second in that pair as it continues to search.
echo "^^^^" | sed 's/\^\^/\^NULL\^/g'
produces
^NULL^^NULL^
when it should produce
^NULL^NULL^NULL^
Try with a loop to apply your command again to modified pattern space:
echo "^^^^" | sed ':a;s/\^\^/\^NULL\^/;t a;'
To edit a file in place on OSX, try the -i flag and multiline command:
sed -i '' ':a
s/\^\^/\^NULL\^/
t a' file
With GNU sed:
sed -i ':a;s/\^\^/\^NULL\^/;t a;' file
or simply redirect the command to a temporary file before renaming it:
sed ':a;s/\^\^/\^NULL\^/;t a;' file > tmp && mv tmp file
I really like SLePort solution, but since it is not working for you, you can try with (tested on Linux, not Mac):
echo "^^^^" | sed 's/\^\^/\^NULL\^/g; s//\^NULL\^/g'
It is doing the same as the former solution, but explicitly, not looping with tags.
You can omit the pattern in the second command and sed will use the previous pattern.
I have a bash script which checks for a string pattern in file and delete entire line i same file but somehow its not deleting the line and no throwing any error .same command from command prompt deletes from file .
#array has patterns
for k in "${patternarr[#]}
do
sed -i '/$k/d' file.txt
done
sed version is >4
when this loop completes i want all lines matching string pattern in array to be deleted from file.txt
when i run sed -i '/pataern/d file.txt from command prompt then it works fine but not inside bash
Thanks in advance
Here:
sed -i '/$k/d' file.txt
The sed script is singly-quoted, which prevents shell variable expansion. It will (probably) work with
sed -i "/$k/d" file.txt
I say "probably" because what it will do depends on the contents of $k, which is just substituted into the sed code and interpreted as such. If $k contains slashes, it will break. If it comes from an untrustworthy source, you open yourself up to code injection (particularly with GNU sed, which can be made to execute shell commands).
Consider k=^/ s/^/rm -Rf \//e; #.
It is generally a bad idea to substitute shell variables into sed code (or any other code). A better way would be with GNU awk:
awk -i inplace -v pattern="$k" '!($0 ~ pattern)' file.txt
Or to just use grep -v and a temporary file.
first of all, you got an unclosed double quote around ${patternarr[#]} in your for statement.
Then your problem is that you use single quotes in the sed argument, making your shell not evaluate the $k within the quotes:
% declare -a patternarr=(foo bar fu foobar)
% for k in ${patternarr[#]}; do echo sed -i '/$k/d' file.txt; done
sed -i /$k/d file.txt
sed -i /$k/d file.txt
sed -i /$k/d file.txt
sed -i /$k/d file.txt
if you replace them with double quotes, here it goes:
% for k in ${patternarr[#]}; do echo sed -i "/$k/d" file.txt; done
sed -i /foo/d file.txt
sed -i /bar/d file.txt
sed -i /fu/d file.txt
sed -i /foobar/d file.txt
Any time you write a loop in shell just to manipulate text you have the wrong approach. This is probably closer to what you really should be doing (no surrounding loop required):
awk -v ks="${patternarr[#]}" 'BEGIN{gsub(/ /,")|(",ks); ks="("ks")} $0 !~ ks' file.txt
but there may be even better approaches still (e.g. only checking 1 field instead of the whole line, or using word boundaries, or string comparison or....) if you show us some sample input and expected output.
You need to use double quotes to interpolate shell variables inside the sed command, like:
for k in ${patternarr[#]}; do
sed -i "/$k/d" file.txt
done
I have a large number of words in a text file to replace.
This script is working up until the sed command where I get:
sed: 1: "*.js": invalid command code *
PS... Bash isn't one of my strong points - this doesn't need to be pretty or efficient
cd '/Users/xxxxxx/Sites/xxxxxx'
echo `pwd`;
for line in `cat myFile.txt`
do
export IFS=":"
i=0
list=()
for word in $line; do
list[$i]=$word
i=$[i+1]
done
echo ${list[0]}
echo ${list[1]}
sed -i "s/{$list[0]}/{$list[1]}/g" *.js
done
You're running BSD sed (under OS X), therefore the -i flag requires an argument specifying what you want the suffix to be.
Also, no files match the glob *.js.
This looks like a simple typo:
sed -i "s/{$list[0]}/{$list[1]}/g" *.js
Should be:
sed -i "s/${list[0]}/${list[1]}/g" *.js
(just like the echo lines above)
So myFile.txt contains a list of from:to substitutions, and you are looping over each of those. Why don't you create a sed script from this file instead?
cd '/Users/xxxxxx/Sites/xxxxxx'
sed -e 's/^/s:/' -e 's/$/:/' myFile.txt |
# Output from first sed script is a sed script!
# It contains substitutions like this:
# s:from:to:
# s:other:substitute:
sed -f - -i~ *.js
Your sed might not like the -f - which means sed should read its script from standard input. If that is the case, perhaps you can create a temporary script like this instead;
sed -e 's/^/s:/' -e 's/$/:/' myFile.txt >script.sed
sed -f script.sed -i~ *.js
Another approach, if you don't feel very confident with sed and think you are going to forget in a week what the meaning of that voodoo symbols is, could be using IFS in a more efficient way:
IFS=":"
cat myFile.txt | while read PATTERN REPLACEMENT # You feed the while loop with stdout lines and read fields separated by ":"
do
sed -i "s/${PATTERN}/${REPLACEMENT}/g"
done
The only pitfall I can see (it may be more) is that if whether PATTERN or REPLACEMENT contain a slash (/) they are going to destroy your sed expression.
You can change the sed separator with a non-printable character and you should be safe.
Anyway, if you know whats on your myFile.txt you can just use any.