This is the command working for me:
sed "50,99999{/^\s*printf/d}" the_file
So this command delete all the lines between 50 and 99999 which have "printf" in it and there is only whitespace before printf at the line.
Now my questions are:
how to replace 99999 with some meta symbol to indicate the real line number
I tried sed "50,${/^\s*PUTS/d}" the_file, but it is not right.
how to replace "printf" with an environment variable? I tried
set pattern printf
sed "50,99999{/^\s*$pattern/d}" the_file
but it is not right.
Assuming a Bourne-like shell such as bash:
Simply define shell variables and splice them into your sed command string:
endLine=99999
pattern='printf'
sed '50,'"$endLine"'{ /^\s*'"$pattern"'/d; }' the_file
Note that the static parts of the sed command strings are single-quoted, as that protects them from interpretation by the shell (which means you needn't quote $ and `, for instance).
You can put everything into a single double-quoted string so as to be able to embed variable references directly, but distinguishing between what the shell will interpret up front and what sed will interpret can get confusing quickly.
That said, using a double-quoted string for the case at hand is simple:
sed "50,$endLine { /^\s*$pattern/d; }" the_file
sed "50,${/^\s*PUTS/d}" the_file
this line won't work, because you used double quotes, and you need escape the dollar: \$ or use single quote: '50,${/.../d}' file
sed "50,99999{/^\s*$pattern/d}" file
this line should work.
EDIT
wait, I just noticed that you set env var via set... this is not correct if you were with Bash. you should use export PAT="PUT" in your script.
check #Jonathan and #tripleee 's comments
Related
The following command fails.
sed 's/user=\'mysql\'/user=`whoami`/g' input_file
An example input_file contains the following line
user='mysql'
The corresponding expected output is
user=`whoami`
(Yes, I literally want whoami between backticks, I don't want it to expand my userid.)
This should be what you need:
Using double quotes to enclose the sed command,
so that you are free to use single quotes in it;
escape backticks to avoid the expansion.
sed "s/user='mysql'/user=\`whoami\`/g" yourfile
I've intentionally omitted the -i option for the simple reason that it is not part of the issue.
To clarify the relation between single quotes and escaping, compare the following two commands
echo 'I didn\'t know'
echo 'I didn'\''t know'
The former will wait for further input as there's an open ', whereas the latter will work fine, as you are concatenating a single quoted string ('I didn'), an escaped single quote (\'), and another single quoted string ('t know').
I am trying to add multiple lines to a file, all with a leading a tab. The lines should be inserted on the first line after matching a string.
Assume a file with only one line, called "my-file.txt" as follows:
foo
I have tried the following sed command:
sed "/^foo\$/a \tinsert1\n\tinsert2" my-file.txt
This produces the following output:
foo
tinsert1
insert2
Notice how the the tab that should be on the first (inserted) line is omitted. Instead it prints an extra leading 't'.
Why? And how can I change my command to print the tab on the first line, as expected?
With GNU sed:
sed '/^foo$/a \\tinsert1\n\tinsert2' file
<---- single quotes! --->
Produces:
foo
insert1
insert2
From the manual:
a \
text Append text, which has each embedded newline preceded by a backslash.
Since the text to be append itself has to to be preceded by a backslash, it needs to be \\t at the beginning.
PS: If you need to use double quotes around the sed command because you want to inject shell variables, you need to escape the \ which precedes the text to be appended:
ins1="foo"
ins2="bar"
sed "/^foo\$/a \\\t${ins1}\n\t${ins2}" file
sed is for doing s/old/new on individual strings, that is all. Just use awk:
$ awk '{print} $0=="foo"{print "\tinsert1\n\tinsert2"}' file
foo
insert1
insert2
The above will work using any awk in any shell on every UNIX box and is trivial to modify to do anything else you might want to do in future.
I have one file named `config_3_setConfigPW.ldif? containing the following line:
{pass}
on terminal, I used following commands
SLAPPASSWD=Pwd&0011
sed -i "s#{pass}#$SLAPPASSWD#" config_3_setConfigPW.ldif
It should replace {pass} to Pwd&0011 but it generates Pwd{pass}0011.
The reason is that the SLAPPASSWD shell variable is expanded before sed sees it. So sed sees:
sed -i "s#{pass}#Pwd&0011#" config_3_setConfigPW.ldif
When an "&" is on the right hand side of a pattern it means "copy the matched input", and in your case the matched input is "{pass}".
The real problem is that you would have to escape all the special characters that might arise in SLAPPASSWD, to prevent sed doing this. For example, if you had character "#" in the password, sed would think it was the end of the substitute command, and give a syntax error.
Because of this, I wouldn't use sed for this. You could try gawk or perl?
eg, this will print out the modified file in awk (though it still assumes that SLAPPASSWD contains no " character
awk -F \{pass\} ' { print $1"'${SLAPPASSWD}'"$2 } ' config_3_setConfigPW.ldif
That's because$SLAPPASSWD contains the character sequences & which is a metacharacter used by sed and evaluates to the matched text in the s command. Meaning:
sed 's/{pass}/match: &/' <<< '{pass}'
would give you:
match: {pass}
A time ago I've asked this question: "Is it possible to escape regex metacharacters reliably with sed". Answers there show how to reliably escape the password before using it as the replacement part:
pwd="Pwd&0011"
pwdEscaped="$(sed 's/[&/\]/\\&/g' <<< "$pwd")"
# Now you can safely pass $pwd to sed
sed -i "s/{pass}/$pwdEscaped/" config_3_setConfigPW.ldif
Bear in mind that sed NEVER operates on strings. The thing sed searches for is a regexp and the thing it replaces it with is string-like but has some metacharacters you need to be aware of, e.g. & or \<number>, and all of it needs to avoid using the sed delimiters, / typically.
If you want to operate on strings you need to use awk:
awk -v old="{pass}" -v new="$SLAPPASSWD" 's=index($0,old){ $0 = substr($0,1,s-1) new substr($0,s+length(old))} 1' file
Even the above would need tweaked if old or new contained escape characters.
I am using sed to replace 14 different abbreviations like CA_23456, CB_scaffold34532,... with 'proper' names in a file and it works putting it all on one line.
acc=$1
sed -e 's/CA_[A-Z]*[a-z]*[0-9]*/Hesperocyparis_arizonica/;s/CB_[A-Z]*[a-z]*[0-9]*/Hesperocyparis_bakeri/;s/CM_[A-Z]*[a-z]*[0-9]*/Hesperocyparis_macrocarpa/;s/CS_[A-Z]*[a-z]*[0-9]*/Cupressus_sempervirens/;s/CT_[A-Z]*[a-z]*[0-9]*/Cupressus_torulosa/;s/JD_[A-Z]*[a-z]*[0-9]*/Juniperus_drupacea/;s/JF_[A-Z]*[a-z]*[0-9]*/Juniperus_flaccida/;s/JI_[A-Z]*[a-z]*[0-9]*/Juniperus_indica/;s/JP_[A-Z]*[a-z]*[0-9]*/Juniperus_phoenicea/;s/JX_[A-Z]*[a-z]*[0-9]*/Juniperus_procera/;s/JS_[A-Z]*[a-z]*[0-9]*/Juniperus_scopulorum/;s/MD_[A-Z]*[a-z]*[0-9]*/Microbiota_decussata/;s/XN_[A-Z]*[a-z]*[0-9]*/Xanthocyparis_nootkatensis/;s/XV_[A-Z]*[a-z]*[0-9]*/Xanthocyparis_vietnamensis/' ${acc}.nex > ${acc}_replaced.nex
To make it more readable I'd like to have the command split over multiple lines using '\' (not all the replacements are shown for brevity)
acc=$1
sed -e 's/CA_[A-Z]*[a-z]*[0-9]*/Hesperocyparis_arizonica/;\
s/CB_[A-Z]*[a-z]*[0-9]*/Hesperocyparis_bakeri/;\
s/CM_[A-Z]*[a-z]*[0-9]*/Hesperocyparis_macrocarpa/'\
${acc}.nex > ${acc}_replaced.nex
However, I get an error message: sed: -e expression #1, char 168: unterminated address regex. I have looked at the answers to similar problems on various webforums and tried various things (using 's/.../.../' on every line, leaving ';' out,....) but I can't get it to work. What am I doing wrong?
Drop the \ that escapes the newlines. (They are not actually doing it!, they are interpreted as wrong syntax by sed). However I would suggest to put it into a file and run it like this:
sed -f script.sed input
where script.sed looks like this:
s/CA_[A-Z]*[a-z]*[0-9]*/Hesperocyparis_arizonica/
s/CB_[A-Z]*[a-z]*[0-9]*/Hesperocyparis_bakeri/
s/CM_[A-Z]*[a-z]*[0-9]*/Hesperocyparis_macrocarpa/
Remove the backslashes from the sed code.
Inside singly-quoted shell strings, backslashes are not needed to escape newlines and are not removed because they are not parsed as escape characters. This has the effect that sed sees them as part of its code, and it then expects to find an address regex with a different delimiter than / before the command ends at the next newline (similar to \,/home/, !d). This address regex does not appear (nor an associated command), and so sed complains about invalid code.
Apart from that: The semicolons in the sed code are no longer necessary when you terminate commands with newlines, and anything involving shell variables should be quoted to avoid splitting in case of whitespace.
In sum:
sed -e 's/CA_[A-Z]*[a-z]*[0-9]*/Hesperocyparis_arizonica/
s/CB_[A-Z]*[a-z]*[0-9]*/Hesperocyparis_bakeri/
s/CM_[A-Z]*[a-z]*[0-9]*/Hesperocyparis_macrocarpa/' \
"${acc}.nex" > "${acc}_replaced.nex"
I'm having issues matching strings even if they start with any number of white spaces. It's been very little time since I started using regular expressions, so I need some help
Here is an example. I have a file (file.txt) that contains two lines
#String1='Test One'
String1='Test Two'
Im trying to change the value for the second line, without affecting line 1 so I used this
sed -i "s|String1=.*$|String1='Test Three'|g"
This changes the values for both lines. How can I make sed change only the value of the second string?
Thank you
With gnu sed, you match spaces using \s, while other sed implementations usually work with the [[:space:]] character class. So, pick one of these:
sed 's/^\s*AWord/AnotherWord/'
sed 's/^[[:space:]]*AWord/AnotherWord/'
Since you're using -i, I assume GNU sed. Either way, you probably shouldn't retype your word, as that introduces the chance of a typo. I'd go with:
sed -i "s/^\(\s*String1=\).*/\1'New Value'/" file
Move the \s* outside of the parens if you don't want to preserve the leading whitespace.
There are a couple of solutions you could use to go about your problem
If you want to ignore lines that begin with a comment character such as '#' you could use something like this:
sed -i "/^\s*#/! s|String1=.*$|String1='Test Three'|g" file.txt
which will only operate on lines that do not match the regular expression /.../! that begins ^ with optional whiltespace\s* followed by an octothorp #
The other option is to include the characters before 'String' as part of the substitution. Doing it this way means you'll need to capture \(...\) the group to include it in the output with \1
sed -i "s|^\(\s*\)String1=.*$|\1String1='Test Four'|g" file.txt
With GNU sed, try:
sed -i "s|^\s*String1=.*$|String1='Test Three'|" file
or
sed -i "/^\s*String1=/s/=.*/='Test Three'/" file
Using awk you could do:
awk '/String1/ && f++ {$2="Test Three"}1' FS=\' OFS=\' file
#String1='Test One'
String1='Test Three'
It will ignore first hits of string1 since f is not true.