I would like to replace double or more tabs in a string with one using sed. However, when I do
echo "A\t\tB\t\tC" | sed 's/\t\t/\t/g'
I get the same thing back
A\t\tB\t\tC
How can I get this?
A\tB\tC
Thanks in advance!
It looks like you already got it - you just missed a flag to echo => -e
$ echo -e "A\t\tB\t\tC" | sed -e 's/\t\t/\t/g'
A B C
$ echo -e "A\t\tB\t\tC"
A B C
Update: don't forget the -e on sed!
Related
i have text like 1|2|3||| , and try to replace each || with |0|, my command is following
echo '1|2|3|||' | sed -e 's/||/|0|/g'
but get result 1|2|3|0||, the pattern is only replaced once.
could someone help me improve the command, thx
Just do it 2 times
l_replace='s#||#|0|#g'
echo '1|2|3||||||||4||5|||' | sed -e "$l_replace;$l_replace"
Using any sed or any awk in any shell on every Unix box:
$ echo '1|2|3|||' | sed -e 's/||/|0|/g; s/||/|0|/g'
1|2|3|0|0|
$ echo '1|2|3|||' | awk '{while(gsub(/\|\|/,"|0|"));}1'
1|2|3|0|0|
This might work for you (GNU sed):
sed 's/||/|0|/g;s//[0]/g' file
or:
sed ':a;s/||/|0|/g;ta' file
The replacement needs to actioned twice because part of the match is in the replacement.
I'm trying to convert a predefined string %c# where # can be some number with another string. The catch is that the length of the other string must be truncated to # number of characters.
Ideally these set of commands would work:
FORMAT="%c10"
LAST_COMMIT="5189e42b14797b1e36ffb7fc5657c7eea08f1c0f"
echo $FORMAT | sed "s/%c\([0-9]\+\)/${LAST_COMMIT:0:\1}/g"
but clearly there is a syntax error on the \1. You can replace it with a number to see what I'm trying to get as output.
I'm open to using some other program other than sed to achieve this but ideally it should be programs that are pretty much native to most linux installations.
Thanks!
This is my idea.
echo ${LAST_COMMIT} | head -c $(echo ${FORMAT} | sed -e 's/%c//')
Get number with sed and get first some character with head.
EDIT1
This might be better.
echo ${LAST_COMMIT} | head -c $(echo ${FORMAT} | sed -e 's/%c\([0-9]\+\)/\1/')
EDIT2
I make the script because it is too tough to understand. Please try this.
$ cat sample.sh
#!/bin/bash
FORMAT="%b-%t-%c10-%c5"
LAST_COMMIT="5189e42b14797b1e36ffb7fc5657c7eea08f1c0f"
## List numbers
lengths=$(echo ${FORMAT} | sed -e "s/%[^c]//g" -e "s/-//g" -e "s/%c/ /g")
## Substitute %cXX to first XX characters of LAST_COMMIT
for n in ${lengths}
do
to_str=$(echo ${LAST_COMMIT:0:${n}})
FORMAT=$(echo ${FORMAT} | sed "s/%c${length}/${to_str}/")
done
## Print result
echo ${FORMAT}
This is the result.
$ ./sample.sh
%b-%t-5189e42b1410-5189e5
Also this is one line commands (Same contents but too long and too tough)
for n in $(echo ${FORMAT} | sed -e "s/%[^c]//g" -e "s/-//g" -e "s/%c/ /g"); do to_str=$(echo ${LAST_COMMIT:0:${n}}); FORMAT=$(echo ${FORMAT} | sed "s/%c${length}/${to_str}/"); done; echo ${FORMAT}
The value of $LAST_COMMIT gets interpolated before sed runs, so there is no backreference to refer back to yet. There is an /e extension in GNU sed which would support something like this, but I would simply use a slightly more capable tool.
perl -e '$fmt = shift; $fmt=~ s/%c(\d+)/%.$1s/g; printf("$fmt\n", #ARGV)' '%c10' "$LAST_COMMIT"
Of course, if you can let go of your own ad-hoc format string specifier, and switch to a printf-compatible format string altogether, just use the printf shell command straight off.
length=$(echo $FORMAT | sed "s/%c\([0-9]\+\)/\1/g")
echo "${LAST_COMMIT:0:$length}"
How to remove words that do not start with a specific character by sed?
Sample:
echo "--foo imhere -abc anotherone" | sed ...
Result must be;
"--foo -abc"
echo "--foo imhere -abc anotherone" |\
sed -e 's/^/ /g' -e 's/ [^-][^ ]*//g' -e 's/^ *//g'
The first and last -e commands are needed if only when the first word can be wrong either.
gnu sed with -r:
kent$ echo "--foo imhere -abc anotherone" | sed -r 's/^|\s[^-]\S*//g'
--foo -abc
However I prefer awk to solve it, more straightforward:
awk '{for(i=1;i<=NF;i++)$i=($i~/^-/?$i:"")}7'
output:
--foo -abc
You can use ssed to enable PCRE regex and then you can use this one:
(?<!-)\b\w+
Working demo
echo "--foo imhere -abc anotherone" | ssed 's/(?<!-)\b\w+//'
In bash I need to shave a first and/or last character from string, but only if it is a certain character.
If I have | I need
/foo/bar/hah/ => foo/bar/hah
foo/bar/hah => foo/bar/hah
You can downvote me for not listing everything I've tried. But the fact is I've tried at least 35 differents sed strings and bash character stuff, many of which was from stack overflow. I simply cannot get this to happen.
what's the problem with the simple one?
sed "s/^\///;s/\/$//"
Output is
foo/bar/hah
foo/bar/hah
In pure bash :
$ var=/foo/bar/hah/
$ var=${var%/}
$ echo ${var#/}
foo/bar/hah
$
Check bash parameter expansion
or with sed :
$ sed -r 's#(^/|/$)##g' file
How about simply this:
echo "$x" | sed -e 's:^/::' -e 's:/$::'
Further to #sputnick's answer and from this answer, here's a function that would do it:
STR="/foo/bar/etc/";
STRB="foo/bar/etc";
function trimslashes {
STR="$1"
STR=${STR#"/"}
STR=${STR%"/"}
echo "$STR"
}
trimslashes $STR
trimslashes $STRB
# foo/bar/etc
# foo/bar/etc
echo '/foo/bar/hah/' | sed 's#^/##' | sed 's#/$##'
assuming the / character is the only one you're trying to remove, then sed -E 's_^[/](.*)_\1_' should do the job:
$ echo "$var1"; echo "$var2"
/foo/bar/hah
foo/bar/hah
$ echo "$var1" | sed -E 's_^[/](.*)_\1_'
foo/bar/hah
$ echo "$var2" | sed -E 's_^[/](.*)_\1_'
foo/bar/hah
if you also need to replace other characters at the start of the line, add it to the [/] class. for example, if you need to replace / or -, it would be sed -E 's_^[/-](.*)_\1_'
Here is an awk version:
echo "/foo/bar/hah/" | awk '{gsub(/^\/|\/$/,"")}1'
foo/bar/hah
I need to replace characters from 10th to 20th in the string which looks like that:
123456789012345678901234567890
So far I've tried:
a)
Works for the 10th character ONLY:
echo "123456789012345678901234567890" | sed 's/./X/10'
b)
Doesn't work on the range:
echo "123456789012345678901234567890" | sed 's/./X/10,20'
echo "123456789012345678901234567890" | sed 's/./X/10\,20'
echo "123456789012345678901234567890" | sed 's/./X/\{10,20\}'
echo "123456789012345678901234567890" | sed 's/./X/\{10\,20\}'
Does not work and I get error
unknown option to `s'
So - the question is - how do I make this to work:
echo "123456789012345678901234567890" | sed 's/./X/10,20'
Try:
$ sed -r "s/^(.{9})(.{11})/\1XXXXXXXXXX/" <<< 123456789012345678901234567890
123456789XXXXXXXXXX1234567890
It is a complex sed problem, I could just find this solution:
$ sed 's/^\(.\{10\}\)\(.\{10\}\)/\1XXXXXXXXXX/' <<< 123456789012345678901234567890
1234567890XXXXXXXXXX1234567890
With awk it looks nicer:
$ awk 'BEGIN{FS=OFS=""} {for (i=10;i<=20;i++) $i="X"} {print}' <<< 123456789012345678901234567890
123456789XXXXXXXXXXX1234567890
You can do it with bash parameter substitution like this:
#!/bin/bash
s="123456789012345678901234567890"
l=${s:0:9} # Extract left part
m=${s:10:11} # Extract middle part
r=${s:20} # Extract right part
# Diddle with middle part to your heart's content and re-assemble "$l$m$r" when done
m=$(sed 's/./X/g' <<<$m)
See here for more explanation and examples.
Or, you can do this:
transform the row of letters into a column so each is on its own line
apply your edits to LINES 10 through 20 (as opposed to characters 10 through 20)
transform column of letters back into a row (by deleting linefeeds)
as shown in the one-liner below:
$ echo "123456789012345678901234567890" | sed "s/\(.\)/\1\n/g" | sed "10,20s/./X/" | tr -d "\n"
I know, that it looks ugly, but:
echo "123456789012345678901234567890" | \
sed 's/^\(.\{10\}\).\{10\}\(.*\)/\1XXXXXXXXXX\2/'
Without placing multiple X in sed command:
sed -r 's/^(.{9})(.{10,20})(.*)$/\1\n\2\n\3/' | sed -e '2s/./X/g' -e 'N;N;s/\n//g'
To replace the 10th to 20th characters, inclusive, try:
echo 123456789012345678901234567890 | sed 's/\(.\{9\}\).\{11\}/\1XXXXXXXXXX/'
123456789XXXXXXXXXX1234567890
With the GNU sed, you can use the -r switch to remove most of the backslashes:
echo 123456789012345678901234567890 | sed -r 's/(.{9}).{11}/\1XXXXXXXXXX/'
Or the naive approach also works here:
echo 123456789012345678901234567890 | sed 's/\(.........\).........../\1XXXXXXXXXX/'
This might work for you (GNU sed):
sed ':a;/.\{9\}X\{11\}/!s/\(.\{9\}X*\)./\1X/;ta' file
or with a bit of syntactic sugar:
sed -r ':a;/.{9}X{11}/!s/(.{9}X*)./\1X/;ta' file