I have variable data with digits and minus "[-]", "[0-9]". It's may be:
source NUMBER ->result NUMBER AFTER MODIFY
XXX ->0.XXX,
XXXX ->X.XXX,
XXXXX ->XX.XXX,
-XXX -> -0.XXX,
-XXXX ->-X.XXX,
-XXXXX ->-XX.XXX,
Can this be done with sed?
I'd say:
sed -r 's/[0-9]{3}$/.&/; s/^(-?)\./\10./' filename
That is:
s/[0-9]{3}$/.&/ # put a dot before the last three digits in a line
s/^(-?)\./\10./ # if the result of this begins with . or -., insert a 0
# before the .
-r requires GNU sed. If you're on BSD or Mac OS X, which comes with BSD sed, you could use
sed 's/[0-9]\{3\}$/.&/;s/^\(-\?\)\./\10./' filename
That's the same thing with basic instead of extended regex syntax.
Addendum: Come to think of it, this appears to be equivalent to
awk '{ printf("%.3f\n", $0 / 1000) }' filename
sed 's/\(-*\)\(.*\)\(...\)/\10\2.\3/;s/0\([1-9]\)/\1/' YourFile
another way, remove 0 if needed and without back reference
perl -pe 's/(\d{3})\b/.$1/;
s/\B\./0./' file
line1 : 222<word-boundary> --> .222
line2 : <non-word-boundary>.222 --> 0.222
Related
I need help figuring out the syntax or what command to use to find an replace a specific number in a file.
I need to replace the number 10 with 25 in a configuration file. I have tried the following:
sed 's/10/25/g' /etc/security/limits.conf
This changes other instances that contain 10 such as 1000 and 10000 to 2500 and 25000, I need to juct change the need to just change 10 to 25. Please help.
Thank you,
Joseph
The trick here is to limit the sed substitution to the line you want to change. For limits.conf you are best off matching the domain, type and item. So if you wanted to just change a limit for domain #student, type hard, item nproc, you'd use something like
sed '/#student.*hard.*nproc/s/10/25/g' /etc/security/limits.conf
sed -ri '/^#/!s/(^.*)([[:space:]]10$)/\1 25/' /etc/security/limits.conf
With regular expression interpretation enabled (-r or -E), process all lines that don't start with a # by using ! We then split the lines into two sections, and replace the line for the first section followed by a space and 25. The $ ensure that the entry to replace is anchored at the end of the line.
Awk is another option:
awk -i 'NF==4 && $4==10 { gsub("10","25",$4) }1' /etc/security/limits.conf
Check if the line has 4 space delimited fields (NF==4) and the 4th field ($4) is 10. If this condition is met, replace 10 with 25 using gsub and print all lines with 1
The -i is an inplace amend flag on more recent versions of awk. If a compliant version is not available, use:
awk 'NF==4 && $4==10 { gsub("10","25",$4) }1' /etc/security/limits.conf > /etc/security/limits.tmp && mv -f /etc/security/limits.tmp /etc/security/limits.conf
Use this Perl one-liner, where \b stands for word break (so that 10 will not match 210 or 102):
perl -pe 's/\b10\b/25/g' in_file > out_file
Or to change the file in-place:
perl -i.bak -pe 's/\b10\b/25/g' in_file
The Perl one-liner uses these command line flags:
-e : Tells Perl to look for code in-line, instead of in a file.
-p : Loop over the input one line at a time, assigning it to $_ by default. Add print $_ after each loop iteration.
-i.bak : Edit input files in-place (overwrite the input file). Before overwriting, save a backup copy of the original file by appending to its name the extension .bak.
The regex uses modifier /g : Match the pattern repeatedly.
SEE ALSO:
perldoc perlrun: how to execute the Perl interpreter: command line switches
perldoc perlrequick: Perl regular expressions quick start
I have a text file that looks like this:
qwerty=1.8
asdfg=15.9
zxcvb=144.99
I managed to replace a specific version with another specific version using sed:
sed s/asdfg=15.9/asdfg=15.10/ file
But how can i make it dynamic? My end goal is a command that i can use with argument "asdfg" and it will update the line asdfg=15.9 to asdfg=15.10 without me having to know the version.
With GNU awk:
$ # adds 1 to entire number after =
$ awk 'match($0, /(asdfg=)(.+)/, m){$0 = m[1] m[2]+1} 1' file
qwerty=1.8
asdfg=16.9
zxcvb=144.99
$ # adds 1 after the decimal point
$ awk 'match($0, /(asdfg=[0-9]+\.)(.+)/, m){$0 = m[1] m[2]+1} 1' file
qwerty=1.8
asdfg=15.10
zxcvb=144.99
Here match is used to separate out the prefix string and the number to be incremented. The results are available from m array.
With perl
$ perl -pe 's/asdfg=\K.+/$&+1/e' file
qwerty=1.8
asdfg=16.9
zxcvb=144.99
The e flag allows you to use Perl code in replacement section. \K is used here to avoid asdfg= showing up in matched portion. $& will have the matched portion, which is the number after asdfg= in this case.
To change only after the decimal point:
$ perl -pe 's/asdfg=\d*\.\K.+/$&+1/e' ip.txt
qwerty=1.8
asdfg=15.10
zxcvb=144.99
Use perl -i -pe to write the changes back to file. Use -i.bkp to create backups.
I'm currently trying to find a line in a file
#define IMAX 8000
and replacing 8000 with another number.
Currently, stuck trying to pipe arguments from awk into sed.
grep '#define IMAX' 1d_Euler_mpi_test.c | awk '{print $3}' | sed
Not too sure how to proceed from here.
I would do something like:
sed -i '' '/^#define IMAX 8000$/s/8000/NEW_NUMBER/' 1d_Euler_mpi_test.c
Could you please try following. Place new number's value in place of new_number too.(tested this with GNU sed)
echo "#define IMAX 8000" | sed -E '/#define IMAX /s/[0-9]+$/new_number/'
In case you are reading input from an Input_file and want to save its output into Input_file itself use following then.
sed -E '/#define IMAX /s/[0-9]+$/new_number/' Input_file
Add -i flag in above code in case you want to save output into Input_file itself. Also my codes will catch any digits which are coming at the end of the line which has string #define IMAX so in case you only want to look for 8000 or any fixed number change [0-9]+$ to 8000 etc in above codes then.
You may use GNU sed.
sed -i -e 's/IMAX 8000/IMAX 9000/g' /tmp/file.txt
Which will invoke sed to do an in-place edit due to the -i option. This can be called from bash.
If you really really want to use just bash, then the following can work:
while read a ; do echo ${a//IMAX 8000/IMAX 9000} ; done < /tmp/file.txt > /tmp/file.txt.t ; mv /tmp/file.txt{.t,}
This loops over each line, doing a substitution, and writing to a temporary file (don't want to clobber the input). The move at the end just moves temporary to the original name.
I'm trying to remove endlines for all lines in my file where the endline splits two equal signs
ie:
1
a=
=b
2
to
1
a==b
2
I have
sed -i.bak -e 's/=\n =//g' fileName
however, it doesn't seem to make any changes to my file. Is my script correct?
Try this. It saves the whole file content in pattern space and the removes all newline characters between equal signs.
sed -i.bak -e ':a ; $! { N; b a }; s/=\n=/==/g' fileName
It yields:
1
a==b
2
This might work for you (GNU sed):
sed '$!N;s/=\n=/==/;P;D' file
or
sed -e '$!N' -e 's/='$"\n"'=/==/' -e 'P' -e 'D' file
Different seds on different OSs treat newlines in different ways. The most portable way to specify a newline in sed is to use backslash before a return:
sed -e 's/=\
=//g' file
BUT that's not going to work for you until you invoke some other magic sed characters to slurp up multiple lines into a buffer, etc....
Just use awk:
$ cat file
1
a=
=b
2
$ awk '{printf "%s%s", $0, (/=$/ ? "" : "\n")}' file
1
a==b
2
Just prints the current line followed by nothing if the current line ends in an "=" or a newline otherwise. Couldn't be simpler and it's highly portable....
Oh, and if you want to change your original file, that's just:
awk '{printf "%s%s", $0, (/=$/ ? "" : "\n")}' file > tmp && mv tmp file
We have a process which can use a file containing sed commands to alter piped input.
I need to replace a placeholder in the input with a variable value, e.g. in a single -e type of command I can run;
$ echo "Today is XX" | sed -e "s/XX/$(date +%F)/"
Today is 2012-10-11
However I can only specify the sed aspects in a file (and then point the process at the file), E.g. a file called replacements.sed might contain;
s/XX/Thursday/
So obviously;
$ echo "Today is XX" | sed -f replacements.sed
Today is Thursday
If I want to use an environment variable or shell value, though, I can't find a way to make it expand, e.g. if replacements.txt contains;
s/XX/$(date +%F)/
Then;
$ echo "Today is XX" | sed -f replacements.sed
Today is $(date +%F)
Including double quotes in the text of the file just prints the double quotes.
Does anyone know a way to be able to use variables in a sed file?
This might work for you (GNU sed):
cat <<\! > replacements.sed
/XX/{s//'"$(date +%F)"'/;s/.*/echo '&'/e}
!
echo "Today is XX" | sed -f replacements.sed
If you don't have GNU sed, try:
cat <<\! > replacements.sed
/XX/{
s//'"$(date +%F)"'/
s/.*/echo '&'/
}
!
echo "Today is XX" | sed -f replacements.sed | sh
AFAIK, it's not possible. Your best bet will be :
INPUT FILE
aaa
bbb
ccc
SH SCRIPT
#!/bin/sh
STRING="${1//\//\\/}" # using parameter expansion to prevent / collisions
shift
sed "
s/aaa/$STRING/
" "$#"
COMMAND LINE
./sed.sh "fo/obar" <file path>
OUTPUT
fo/obar
bbb
ccc
As others have said, you can't use variables in a sed script, but you might be able to "fake" it using extra leading input that gets added to your hold buffer. For example:
[ghoti#pc ~/tmp]$ cat scr.sed
1{;h;d;};/^--$/g
[ghoti#pc ~/tmp]$ sed -f scr.sed <(date '+%Y-%m-%d'; printf 'foo\n--\nbar\n')
foo
2012-10-10
bar
[ghoti#pc ~/tmp]$
In this example, I'm using process redirection to get input into sed. The "important" data is generated by printf. You could cat a file instead, or run some other program. The "variable" is produced by the date command, and becomes the first line of input to the script.
The sed script takes the first line, puts it in sed's hold buffer, then deletes the line. Then for any subsequent line, if it matches a double dash (our "macro replacement"), it substitutes the contents of the hold buffer. And prints, because that's sed's default action.
Hold buffers (g, G, h, H and x commands) represent "advanced" sed programming. But once you understand how they work, they open up new dimensions of sed fu.
Note: This solution only helps you replace entire lines. Replacing substrings within lines may be possible using the hold buffer, but I can't imagine a way to do it.
(Another note: I'm doing this in FreeBSD, which uses a different sed from what you'll find in Linux. This may work in GNU sed, or it may not; I haven't tested.)
I am in agreement with sputnick. I don't believe that sed would be able to complete that task.
However, you could generate that file on the fly.
You could change the date to a fixed string, like
__DAYOFWEEK__.
Create a temp file, use sed to replace __DAYOFWEEK__ with $(date +%Y).
Then parse your file with sed -f $TEMPFILE.
sed is great, but it might be time to use something like perl that can generate the date on the fly.
To add a newline in the replacement expression using a sed file, what finally worked for me is escaping a literal newline. Example: to append a newline after the string NewLineHere, then this worked for me:
#! /usr/bin/sed -f
s/NewLineHere/NewLineHere\
/g
Not sure it matters but I am on Solaris unix, so not GNU sed for sure.