I have a many repeated content as give below in a file . These are only uniq content.
CHECKSUM="Y"
CHECKSUM="N"
CHECKSUM="U"
CHECKSUM="
I want to replace empty field with "Null" and need output as :
CHECKSUM="Y"
CHECKSUM="N"
CHECKSUM="U"
CHECKSUM="Null"
What I can think of as :
#First find the matching content
cat file.txt | egrep 'CHECKSUM="Y"|CHECKSUM="N"|CHECKSUM="U"' > file_contain.txt
# Find the content where given string are not there
cat file.txt | egrep -v 'CHECKSUM="Y"|CHECKSUM="N"|CHECKSUM="U"' > file_donot_contain.txt
# Replace the string in content not found file
sed -i 's/CHECKSUM="/CHECKSUM="Null"/g' file_donot_contain.txt
# Merge the files
cat file_contain.txt file_donot_contain.txt > output.txt
But I find this is not efficient way of doing. Any other suggestion ?
To achieve this you need to mark that this is the end of the line, not just part of it, using $ (And optionally ^ to mark the start of the line too):
sed -i s'/^CHECKSUM="$/CHECKSUM="Null"/' file.txt
For example I have a file test.json that contains a series of line containing:
header{...}
body{...}
other text (as others)
empty lines
I wanted to run a script that returns the following
Counted started on : test.json
- headers : 4
- body : 5
- <others>
Counted finished : <time elapsed>
What I got so far is this.
count_file() {
echo "Counted started on : $1"
#TODO loop
cat $1 | grep header | wc -l
cat $1 | grep body | wc -l
#others
echo "Counted finished : " #TODO timeElapsed
}
Edit:
Edit question and added code snippet
Perl on Command Line
perl -E '$match=$ARGV[1];open(Input, "<", $ARGV[0]);while(<Input>){ ++$n if /$match/g } say $match," ",$n;' your-file your-pattern
For me
perl -E '$match=$ARGV[1];open(Input, "<", $ARGV[0]);while(<Input>){ ++$n if /$match/g } say $match," ",$n;' parsing_command_line.pl my
It counts how many number of pattern my are, in my script parsing_command_line.pl
output
my 3
For you
perl -E '$match=$ARGV[1];open(Input, "<", $ARGV[0]);while(<Input>){ ++$n if /$match/g } say $match," ",$n;' test.json headers
NOTE
Write all code in one line on your command prompt
First argument is your file
Second is your pattern
This is not a complete code since you have to enter all your pattern one-by-one
You can capture the result of a commande in a variable, like:
result=`cat $1 | grep header | wc -l`
and then print the result:
echo "# headers : $b"
` is the eval operator that let replace the whole expression by the output of the command inside.
How to I concatenate stdin to a string, like this?
echo "input" | COMMAND "string"
and get
inputstring
A bit hacky, but this might be the shortest way to do what you asked in the question (use a pipe to accept stdout from echo "input" as stdin to another process / command:
echo "input" | awk '{print $1"string"}'
Output:
inputstring
What task are you exactly trying to accomplish? More context can get you more direction on a better solution.
Update - responding to comment:
#NoamRoss
The more idiomatic way of doing what you want is then:
echo 'http://dx.doi.org/'"$(pbpaste)"
The $(...) syntax is called command substitution. In short, it executes the commands enclosed in a new subshell, and substitutes the its stdout output to where the $(...) was invoked in the parent shell. So you would get, in effect:
echo 'http://dx.doi.org/'"rsif.2012.0125"
use cat - to read from stdin, and put it in $() to throw away the trailing newline
echo input | COMMAND "$(cat -)string"
However why don't you drop the pipe and grab the output of the left side in a command substitution:
COMMAND "$(echo input)string"
I'm often using pipes, so this tends to be an easy way to prefix and suffix stdin:
echo -n "my standard in" | cat <(echo -n "prefix... ") - <(echo " ...suffix")
prefix... my standard in ...suffix
There are some ways of accomplish this, i personally think the best is:
echo input | while read line; do echo $line string; done
Another can be by substituting "$" (end of line character) with "string" in a sed command:
echo input | sed "s/$/ string/g"
Why i prefer the former? Because it concatenates a string to stdin instantly, for example with the following command:
(echo input_one ;sleep 5; echo input_two ) | while read line; do echo $line string; done
you get immediatly the first output:
input_one string
and then after 5 seconds you get the other echo:
input_two string
On the other hand using "sed" first it performs all the content of the parenthesis and then it gives it to "sed", so the command
(echo input_one ;sleep 5; echo input_two ) | sed "s/$/ string/g"
will output both the lines
input_one string
input_two string
after 5 seconds.
This can be very useful in cases you are performing calls to functions which takes a long time to complete and want to be continuously updated about the output of the function.
You can do it with sed:
seq 5 | sed '$a\6'
seq 5 | sed '$ s/.*/\0 6/'
In your example:
echo input | sed 's/.*/\0string/'
I know this is a few years late, but you can accomplish this with the xargs -J option:
echo "input" | xargs -J "%" echo "%" "string"
And since it is xargs, you can do this on multiple lines of a file at once. If the file 'names' has three lines, like:
Adam
Bob
Charlie
You could do:
cat names | xargs -n 1 -J "%" echo "I like" "%" "because he is nice"
Also works:
seq -w 0 100 | xargs -I {} echo "string "{}
Will generate strings like:
string 000
string 001
string 002
string 003
string 004
...
The command you posted would take the string "input" use it as COMMAND's stdin stream, which would not produce the results you are looking for unless COMMAND first printed out the contents of its stdin and then printed out its command line arguments.
It seems like what you want to do is more close to command substitution.
http://www.gnu.org/software/bash/manual/html_node/Command-Substitution.html#Command-Substitution
With command substitution you can have a commandline like this:
echo input `COMMAND "string"`
This will first evaluate COMMAND with "string" as input, and then expand the results of that commands execution onto a line, replacing what's between the ‘`’ characters.
cat will be my choice: ls | cat - <(echo new line)
With perl
echo "input" | perl -ne 'print "prefix $_"'
Output:
prefix input
A solution using sd (basically a modern sed; much easier to use IMO):
# replace '$' (end of string marker) with 'Ipsum'
# the `e` flag disables multi-line matching (treats all lines as one)
$ echo "Lorem" | sd --flags e '$' 'Ipsum'
Lorem
Ipsum#no new line here
You might observe that Ipsum appears on a new line, and the output is missing a \n. The reason is echo's output ends in a \n, and you didn't tell sd to add a new \n. sd is technically correct because it's doing exactly what you are asking it to do and nothing else.
However this may not be what you want, so instead you can do this:
# replace '\n$' (new line, immediately followed by end of string) by 'Ipsum\n'
# don't forget to re-add the `\n` that you removed (if you want it)
$ echo "Lorem" | sd --flags e '\n$' 'Ipsum\n'
LoremIpsum
If you have a multi-line string, but you want to append to the end of each individual line:
$ ls
foo bar baz
$ ls | sd '\n' '/file\n'
bar/file
baz/file
foo/file
I want to prepend my sql script with "set" statement before running it.
So I echo the "set" instruction, then pipe it to cat. Command cat takes two parameters : STDIN marked as "-" and my sql file, cat joins both of them to one output. Next I pass the result to mysql command to run it as a script.
echo "set #ZERO_PRODUCTS_DISPLAY='$ZERO_PRODUCTS_DISPLAY';" | cat - sql/test_parameter.sql | mysql
p.s. mysql login and password stored in .my.cnf file
Normally I use something like this for processes I run on my servers
./runEvilProcess.sh >> ./evilProcess.log
However I'm currently using Doxygen and it produces lots of duplicate output
Example output:
QGDict::hashAsciiKey: Invalid null key
QGDict::hashAsciiKey: Invalid null key
QGDict::hashAsciiKey: Invalid null key
So you end up with a very messy log
Is there a way I can only add the line to the log file if the line wasn't the last one added.
A poor example (but not sure how to do in bash)
$previousLine = ""
$outputLine = getNextLine()
if($previousLine != $outputLine) {
$outputLine >> logfile.log
$previousLine = $outputLine
}
If the process returns duplicate lines in a row, pipe the output of your process through uniq:
$ ./t.sh
one
one
two
two
two
one
one
$ ./t.sh | uniq
one
two
one
If the logs are sent to the standard error stream, you'll need to redirect that too:
$ ./yourprog 2>&1 | uniq >> logfile
(This won't help if the duplicates come from multiple runs of the program - but then you can pipe your log file through uniq when reviewing it.)
Create a filter script (filter.sh):
while read line; do
if [ "$last" != "$line" ]; then
echo $line
last=$line
fi
done
and use it:
./runEvilProcess.sh | sh filter.sh >> evillog
I have the following log file which contains lines like this
1345447800561|FINE|blah#13|txReq
1345447800561|FINE|blah#13|Req
1345447800561|FINE|blah#13|rxReq
1345447800561|FINE|blah#14|txReq
1345447800561|FINE|blah#15|Req
I am trying extract the first field from each line and depending on whether it belongs to blah#13 or blah#14, blah#15 i am creating the corresponding files using the following script, which seems quite in-efficient in terms of the number of temp files creates. Any suggestions on how I can optimize it ?
cat newLog | grep -i "org.arl.unet.maca.blah#13" >> maca13
cat newLog | grep -i "org.arl.unet.maca.blah#14" >> maca14
cat newLog | grep -i "org.arl.unet.maca.blah#15" >> maca15
cat maca10 | grep -i "txReq" >> maca10TxFrameNtf_temp
exec<blah10TxFrameNtf_temp
while read line
do
echo $line | cut -d '|' -f 1 >>maca10TxFrameNtf
done
cat maca10 | grep -i "Req" >> maca10RxFrameNtf_temp
while read line
do
echo $line | cut -d '|' -f 1 >>maca10TxFrameNtf
done
rm -rf *_temp
Something like this ?
for m in org.arl.unet.maca.blah#13 org.arl.unet.maca.blah#14 org.arl.unet.maca.blah#15
do
grep -i "$m" newLog | grep "txReq" | cut -d' ' -f1 > log.$m
done
I've found it useful at times to use ex instead of grep/sed to modify text files in place without using temps ... saves the trouble of worrying about uniqueness and writability to the temp file and its directory etc. Plus it just seemed cleaner.
In ksh I would use a code block with the edit commands and just pipe that into ex ...
{
# Any edit command that would work at the colon prompt of a vi editor will work
# This one was just a text substitution that would replace all contents of the line
# at line number ${NUMBER} with the word DATABASE ... which strangely enough was
# necessary at one time lol
# The wq is the "write/quit" command as you would enter it at the vi colon prompt
# which are essentially ex commands.
print "${NUMBER}s/.*/DATABASE/"
print "wq"
} | ex filename > /dev/null 2>&1