I'm getting totally crazy with the following script.
The following command works as expected :
echo a | sed 's/a/b/'
Output :
b
But this script doesn't :
test="'s/a/b/'"
echo a | sed $test
Output :
sed: -e expression #1, char 1: unknown command : `''
I should really be stupid, but I don't see what I am missing.
Thanks,
test="'s/a/b/'"
echo a | sed $test
is equivalent to:
test="'s/a/b/'"
echo a | sed "'s/a/b/'"
Obviously sed doesn't understand the command with both " and ', It interprets ' as a command. You can use either one of them:
test='s/a/b/'
Or
test='s/a/b/'
This is because your double wrapping your string. test="'s/a/b'". Sed then gets 's/a/b/' as literal string. You only want sed to receive s/a/b/.
You only need to wrap the string in one set of quotes, otherwise the inner set of quotes will be interpreted as part of the argument.
you may want this:
kent$ test="s/a/b/"
kent$ echo a | sed ${test}
b
or
kent$ echo a | sed $test
b
or
test=s/a/b/
Related
I have a string:
foo="re-9619-add-selling-office";
I'd like to break up the string on the second - (dash) into variable1 and variable2. I want to end up with variable1=re-9619 and variable2=add-selling-office
I tried it using grep and awk, but now I not sure that's the way to go.
Here is a single sed + read way:
foo="re-9619-add-selling-office"
read var1 var2 < <(sed -E 's/^([^-]*-[^-]*)-/\1 /' <<< "$foo")
# check variables
declare -p var1 var2
declare -- var1="re-9619"
declare -- var2="add-selling-office"
Could you please try following once. Where first variable will have value like re-9619 and second shell variable will have value like add-selling-office
first=$(echo "$foo" | sed 's/\([^-]*-[^-]*\)-.*/\1/')
second=$(echo "$foo" | sed 's/\([^-]*\)-\([^-]*\)-\(.*\)/\3/')
Explanation:
echo "$foo" | sed 's/\([^-]*-[^-]*\)-.*/\1/': Printing value of foo variable and passing its output to sed command. In sed I am using substitute capability to perform substitution, \([^-]*-[^-]*\)-.*(which has everything from starting of value to till 2nd occurrence of - in back reference in it). Then substituting whole value with 1st captured back reference value which will become only re-9619.
echo "$foo" | sed 's/\([^-]*\)-\([^-]*\)-\(.*\)/\3/': Logic is same as above mentioned command. Using sed's capability of substitution with using back reference capability of it. Here we are printing everything after 2nd occurrence of -.
NOTE: second=$(echo "$foo" | sed -E "s/$first-(.*)/\1/") could also help as per #User123's comments.
That can be done using parameter expansions, you don't need an external utility.
$ foo="re-9619-add-selling-office"
$ variable2=${foo#*-*-}
$ variable1=${foo%-"$variable2"}
$
$ echo $variable1
re-9619
$ echo $variable2
add-selling-office
You can use cut:
variable1=$(echo $foo | cut -d '-' -f 1-2)
variable2=$(echo $foo | cut -d '-' -f 3-)
This is the result:
>> echo $variable1
re-9619
>> echo $variable2
add-selling-office
I'm processing some data from a text file using a bash script (Ubuntu 12.10).
The basic idea is that I select a certain line from a file using grep. Next, I process the line to get the number with sed. Both the grep and sed command are working. I can echo the number.
But the concatenation of the result with a string goes wrong.
I get different results when combining string when I do a grep command from a variable or a file. The concatenation goes wrong when I grep a file. It works as expected when I grep a variable with the same text as in the file.
What am I doing wrong with the grep from a file?
Contents of test.pdb
REMARK overall = 324.88
REMARK bon = 24.1918
REMARK coup = 0
My script
#!/bin/bash
#Correct function
echo "Working code"
TEXT="REMARK overall = 324.88\nREMARK bon = 24.1918\nREMARK coup = 0\n"
DATA=$(echo -e $TEXT | grep 'overall' | sed -n -e "s/^.*= //p" )
echo "Data: $DATA"
DATA="$DATA;0"
echo $DATA
#Not working
echo ""
echo "Not working code"
DATA=$(grep 'overall' test.pdb | sed -n -e "s/^.*= //p")
echo "Data: $DATA"
DATA="$DATA;0"
echo $DATA
Output
Working code
Data: 324.88
324.88;0
Not working code
Data: 324.88
;04.88
I went crazy with the same issue.
The real problem is that your "test.pdb" has probably a wrong EOL (end of line) character.
Linux EOL: LF (aka \n)
Windows EOL: CR LF (aka \r \n)
This mean that echo and grep will have problem with this extra character (\r), luckily tr, sed and awk manage it correctly.
So you can try also with:
DATA=$(grep 'overall' test.pdb | sed -n -e "s/^.*= //p" | sed -e 2s/\r$//")
or
DATA=$(grep 'overall' test.pdb | sed -n -e "s/^.*= //p" | tr -d '\r')
With awk, it will be more reliable and cleaner I guess :
$ awk '$2=="overall"{print "Working code\nData: " $4 "\n" $4 ";0"}' file.txt
Working code
Data: 324.88
324.88;0
Try this:
SUFFIX=";0"
DATA="${DATA}${SUFFIX}"
I am new to shell scripts. I want to read a file line by line, which contains arguments and if the arguments contains any spaces in it, I want to replace it by enclosing with quotes.
For example if the file (test.dat) contains:
-DtestArgument1=/path/to a/text file
-DtestArgument2=/path/to a/text file
After parsing the above file, shell script should prepare the string with following:
-DtestArgument1="/path/to a/text file" -DtestArgument2="/path/to a/text file"
Here is my shell script:
while read ARGUMENT; do
ARGUMENT=`echo ${ARGUMENT} | tr "\n" " "`
if [[ "${ARGUMENT}" =~ " " ]]; then
ARGUMENT=`echo $ARGUMENT | sed 's/\^(-D.*\)=(.*)/\1=\"\2\"/g'`
NEW_ARGUMENT="${NEW_ARGUMENT} ${ARGUMENT}"
else
echo "doesn't contains spaces"
NEW_ARGUMENT="${NEW_ARGUMENT} ${ARGUMENT}"
fi
done < test.dat
But it's throwing the following error:
sed: -e expression #1, char 28: Unmatched ) or \)
The code should be compatible with all shells.
I think you should simplify the problem. Rather than worrying about spaces, just quote the argument after the =. Something like:
sed -e 's/=/="/' -e 's/$/"/' test.dat | paste -s -d\ -
Should be sufficient. If you really care about spaces, you could try something like:
sed -e '/=.* /{ s/=/="/; s/$/"/; }' test.dat | paste -s -d\ -
That will only notice spaces after the =. Just use / / if you really want to change any line that has a space anywhere.
There's no need to use a while/read loop: just let sed read the file directly.
The sed parentheses should be escaped:
ARGUMENT=`echo $ARGUMENT | sed "s/\^\(-D.*\)=\(.*\)/\1=\"\2\"/g"`
One place you did, in 3 places you forgot... BTW, I generally use " quotation.
If you prefer '-style, do like this:
ARGUMENT=`echo $ARGUMENT | sed 's/\^(-D.*)=(.*)/\1="\2"/g'`
my question seems to be general, but i can't find any answers.
In sed command, how can you replace the substitution pattern by a value returned by a simple bash function.
For instance, I created the following function :
function parseDates(){
#Some process here with $1 (the pattern found)
return "dateParsed;
}
and the folowing sed command :
myCatFile=`sed -e "s/[0-3][0-9]\/[0-1][0-9]\/[0-9][0-9]/& parseDates &\}/p" myfile`
I found that the caracter '&' represents the current pattern found, i'd like it to be passed to my bash function and the whole pattern to be substituted by the pattern found +dateParsed.
Does anybody have an idea ?
Thanks
you can use the "e" option in sed command like this:
cat t.sh
myecho() {
echo ">>hello,$1<<"
}
export -f myecho
sed -e "s/.*/myecho &/e" <<END
ni
END
you can see the result without "e":
cat t.sh
myecho() {
echo ">>hello,$1<<"
}
export -f myecho
sed -e "s/.*/myecho &/" <<END
ni
END
Agree with Glenn Jackman.
If you want to use bash function in sed, something like this :
sed -rn 's/^([[:digit:].]+)/`date -d #&`/p' file |
while read -r line; do
eval echo "$line"
done
My file here begins with a unix timestamp (e.g. 1362407133.936).
Bash function inside sed (maybe for other purposes):
multi_stdin(){ #Makes function accepet variable or stdin (via pipe)
[[ -n "$1" ]] && echo "$*" || cat -
}
sans_accent(){
multi_stdin "$#" | sed '
y/àáâãäåèéêëìíîïòóôõöùúûü/aaaaaaeeeeiiiiooooouuuu/
y/ÀÁÂÃÄÅÈÉÊËÌÍÎÏÒÓÔÕÖÙÚÛÜ/AAAAAAEEEEIIIIOOOOOUUUU/
y/çÇñÑߢÐð£Øø§µÝý¥¹²³ªº/cCnNBcDdLOoSuYyY123ao/
'
}
eval $(echo "Rogério Madureira" | sed -n 's#.*#echo & | sans_accent#p')
or
eval $(echo "Rogério Madureira" | sed -n 's#.*#sans_accent &#p')
Rogerio
And if you need to keep the output into a variable:
VAR=$( eval $(echo "Rogério Madureira" | sed -n 's#.*#echo & | desacentua#p') )
echo "$VAR"
do it step by step. (also you could use an alternate delimiter , such as "|" instead of "/"
function parseDates(){
#Some process here with $1 (the pattern found)
return "dateParsed;
}
value=$(parseDates)
sed -n "s|[0-3][0-9]/[0-1][0-9]/[0-9][0-9]|& $value &|p" myfile
Note the use of double quotes instead of single quotes, so that $value can be interpolated
I'd like to know if there's a way to do this too. However, for this particular problem you don't need it. If you surround the different components of the date with ()s, you can back reference them with \1 \2 etc and reformat however you want.
For instance, let's reverse 03/04/1973:
echo 03/04/1973 | sed -e 's/\([0-9][0-9]\)\/\([0-9][0-9]\)\/\([0-9][0-9][0-9][0-9]\)/\3\/\2\/\1/g'
sed -e 's#[0-3][0-9]/[0-1][0-9]/[0-9][0-9]#& $(parseDates &)#' myfile |
while read -r line; do
eval echo "$line"
done
You can glue together a sed-command by ending a single-quoted section, and reopening it again.
sed -n 's|[0-3][0-9]/[0-1][0-9]/[0-9][0-9]|& '$(parseDates)' &|p' datefile
However, in contrast to other examples, a function in bash can't return strings, only put them out:
function parseDates(){
# Some process here with $1 (the pattern found)
echo dateParsed
}
I have a fairly simple bash shell scripting problem.
I want to sed a piece of text and then assign the result of the sed to a variable.
#!/bin/bash
MOD_DATE=echo $(date) | sed 's/\ /_/g'
echo $MOD_DATE // should show date with spaces replaced with underscores.
I have tried the above and it doesn't work. Can anyone point out what I'm doing wrong?
To collect the output in stdout into a variable, use a command substitution:
MOD_DATE=`echo $(date) | sed 's/\ /_/g'`
# ^ ^
or
MOD_DATE=$(echo $(date) | sed 's/\ /_/g')
# ^^ ^
Maybe this can help:
mod_date = "$(date +"%d_%m_%Y")"
echo "$mod_date"