Print, modify, print again Bash variable - bash

I am looping over a CSV file. Each line of the file is formatted something like this (it's Open Street Maps data):
planet_85.287_27.665_51a5fb91,AcDbEntity:AcDbPolyline,{ [name] Purano
Bus Park-Thimi [type] route [route] microbus [ref] 10 } { [Id] 13.0
[Srid] 3857 [FieldsTableId]
This follows the format:
Layer,SubClasses,ExtendedEntity,Linetype,EntityHandle,Text
I want to add a new column for Name. I can find the name in a line by cutting off everything before [name] and after [. This code successfully creates a new-line delineated file of all of the names (which I open as a CSV and then copy-paste into the original file as a new column).
cat /path/to/myfile.csv | while read line
do
if [[ ${line} == *"name"* ]]
then
printf "$(echo $line | LC_ALL=C sed 's/^.*name\]//g'| LC_ALL=C cut -f1 -d'[') \n"
else
printf "\n"
fi
done >/path/to/newrow.csv
This system is clearly suboptimal - I would far prefer to print the entire final row. But when I replace that printf line with this:
printf "$line,$(echo $line | LC_ALL=C sed 's/^.*name\]//g'| LC_ALL=C cut -f1 -d'[') \n"
It prints the line but not the name. I've tried printing them in separate print statements, printing the line and then echoing the name, saving the name in a variable and then printing, and a number of other techniques, and each time I either a) only print the line, or b) print the name on a new line, which breaks the CSV format.
What am I doing wrong? How can I print the full original line with the name appended as a new column at the end?
NOTE: I am running this in Terminal on macOS Sierra on a MacBook Pro 15" Retina.

If I understand correctly, you want to extract the name between [name] and [type], and append as the new last CSV column. You can do that using capture groups:
sed -e 's/.*\[name\] \(.*\) \[type\].*/&,\1/' < input
Notice the \(.*\) in the middle. That captures the text between [name] and [type].
In the replacement string, & stands for the matched string, which is the entire line, as the pattern starts and ends with .*.
Next the , is a literal comma, and \1 stands for the content of the first capture group, the part matched within \(...\).

Related

Unix bash - using cut to regex lines in a file, match regex result with another similar line

I have a text file: file.txt, with several thousand lines. It contains a lot of junk lines which I am not interested in, so I use the cut command to regex for the lines I am interested in first. For each entry I am interested in, it will be listed twice in the text file: Once in a "definition" section, another in a "value" section. I want to retrieve the first value from the "definition" section, and then for each entry found there find it's corresponding "value" section entry.
The first entry starts with ' gl_ ', while the 2nd entry would look like ' "gl_ ', starting with a '"'.
This is the code I have so far for looping through the text document, which then retrieves the values I am interested in and appends them to a .csv file:
while read -r line
do
if [[ $line == gl_* ]] ; then (param=$(cut -d'\' -f 1 $line) | def=$(cut -d'\' -f 2 $line) | type=$(cut -d'\' -f 4 $line) | prompt=$(cut -d'\' -f 8 $line))
while read -r glline
do
if [[ $glline == '"'$param* ]] ; then val=$(cut -d'\' -f 3 $glline) |
"$project";"$param";"$val";"$def";"$type";"$prompt" >> /filepath/file.csv
done < file.txt
done < file.txt
This seems to throw some syntax errors related to unexpected tokens near the first 'done' statement.
Example of text that needs to be parsed, and paired:
gl_one\User Defined\1\String\1\\1\Some Text
gl_two\User Defined\1\String\1\\1\Some Text also
gl_three\User Defined\1\Time\1\\1\Datetime now
some\junk
"gl_one\1\Value1
some\junk
"gl_two\1\Value2
"gl_three\1\Value3
So effectively, the while loop reads each line until it hits the first line that starts with 'gl_', which then stores that value (ie. gl_one) as a variable 'param'.
It then starts the nested while loop that looks for the line that starts with a ' " ' in front of the gl_, and is equivalent to the 'param' value. In other words, the
script should couple the lines gl_one and "gl_one, gl_two and "gl_two, gl_three and "gl_three.
The text file is large, and these are settings that have been defined this way. I need to collect the values for each gl_ parameter, to save them together in a .csv file with their corresponding "gl_ values.
Wanted regex output stored in variables would be something like this:
first while loop:
$param = gl_one, $def = User Defined, $type = String, $prompt = Some Text
second while loop:
$val = Value1
Then it stores these variables to the file.csv, with semi-colon separators.
Currently, I have an error for the first 'done' statement, which seems to indicate an issue with the quotation marks. Apart from this,
I am looking for general ideas and comments to the script. I.e, not entirely sure I am looking for the quotation mark parameters "gl_ correctly, or if the
semi-colons as .csv separators are added correctly.
Edit: Overall, the script runs now, but extremely slow due to the inner while loop. Is there any faster way to match the two lines together and add them to the .csv file?
Any ideas and comments?
This will generate a file containing the data you want:
cat file.txt | grep gl_ | sed -E "s/\"//" | sort | sed '$!N;s/\n/\\/' | awk -F'\' '{print $1"; "$5"; "$7"; "$NF}' > /filepath/file.csv
It uses grep to extract all lines containing 'gl_'
then sed to remove the leading '"' from the lines that contain one [I have assumed there are no further '"' in the line]
The lines are sorted
sed removes the return from each pair of lines
awk then prints
the required columns according to your requirements
Output routed to the file.
LANG=C sort -t\\ -sd -k1,1 <file.txt |\
sed '
/^gl_/{ # if definition
N; # append next line to buffer
s/\n"gl_[^\\]*//; # if value, strip first column
t; # and start next loop
}
D; # otherwise, delete the line
' |\
awk -F\\ -v p="$project" -v OFS=\; '{print p,$1,$10,$2,$4,$8 }' \
>>/filepath/file.csv
sort lines so gl_... appears immediately before "gl_... (LANG fixes LC_TYPE) - assumes definition appears before value
sed to help ensure matching definition and value (may still fail if duplicate/missing value), and tidy for awk
awk to pull out relevant fields

Convert multi-line csv to single line using Linux tools

I have a .csv file that contains double quoted multi-line fields. I need to convert the multi-line cell to a single line. It doesn't show in the sample data but I do not know which fields might be multi-line so any solution will need to check every field. I do know how many columns I'll have. The first line will also need to be skipped. I don't how much data so performance isn't a consideration.
I need something that I can run from a bash script on Linux. Preferably using tools such as awk or sed and not actual programming languages.
The data will be processed further with Logstash but it doesn't handle double quoted multi-line fields hence the need to do some pre-processing.
I tried something like this and it kind of works on one row but fails on multiple rows.
sed -e :0 -e '/,.*,.*,.*,.*,/b' -e N -e '1n;N;N;N;s/\n/ /g' -e b0 file.csv
CSV example
First name,Last name,Address,ZIP
John,Doe,"Country
City
Street",12345
The output I want is
First name,Last name,Address,ZIP
John,Doe,Country City Street,12345
Jane,Doe,Country City Street,67890
etc.
etc.
First my apologies for getting here 7 months late...
I came across a problem similar to yours today, with multiple fields with multi-line types. I was glad to find your question but at least for my case I have the complexity that, as more than one field is conflicting, quotes might open, close and open again on the same line... anyway, reading a lot and combining answers from different posts I came up with something like this:
First I count the quotes in a line, to do that, I take out everything but quotes and then use wc:
quotes=`echo $line | tr -cd '"' | wc -c` # Counts the quotes
If you think of a single multi-line field, knowing if the quotes are 1 or 2 is enough. In a more generic scenario like mine I have to know if the number of quotes is odd or even to know if the line completes the record or expects more information.
To check for even or odd you can use the mod operand (%), in general:
even % 2 = 0
odd % 2 = 1
For the first line:
Odd means that the line expects more information on the next line.
Even means the line is complete.
For the subsequent lines, I have to know the status of the previous one. for instance in your sample text:
First name,Last name,Address,ZIP
John,Doe,"Country
City
Street",12345
You can say line 1 (John,Doe,"Country) has 1 quote (odd) what means the status of the record is incomplete or open.
When you go to line 2, there is no quote (even). Nevertheless this does not mean the record is complete, you have to consider the previous status... so for the lines following the first one it will be:
Odd means that record status toggles (incomplete to complete).
Even means that record status remains as the previous line.
What I did was looping line by line while carrying the status of the last line to the next one:
incomplete=0
cat file.csv | while read line; do
quotes=`echo $line | tr -cd '"' | wc -c` # Counts the quotes
incomplete=$((($quotes+$incomplete)%2)) # Check if Odd or Even to decide status
if [ $incomplete -eq 1 ]; then
echo -n "$line " >> new.csv # If line is incomplete join with next
else
echo "$line" >> new.csv # If line completes the record finish
fi
done
Once this was executed, a file in your format generates a new.csv like this:
First name,Last name,Address,ZIP
John,Doe,"Country City Street",12345
I like one-liners as much as everyone, I wrote that script just for the sake of clarity, you can - arguably - write it in one line like:
i=0;cat file.csv|while read l;do i=$((($(echo $l|tr -cd '"'|wc -c)+$i)%2));[[ $i = 1 ]] && echo -n "$l " || echo "$l";done >new.csv
I would appreciate it if you could go back to your example and see if this works for your case (which you most likely already solved). Hopefully this can still help someone else down the road...
Recovering the multi-line fields
Every need is different, in my case I wanted the records in one line to further process the csv to add some bash-extracted data, but I would like to keep the csv as it was. To accomplish that, instead of joining the lines with a space I used a code - likely unique - that I could then search and replace:
i=0;cat file.csv|while read l;do i=$((($(echo $l|tr -cd '"'|wc -c)+$i)%2));[[ $i = 1 ]] && echo -n "$l ~newline~ " || echo "$l";done >new.csv
the code is ~newline~, this is totally arbitrary of course.
Then, after doing my processing, I took the csv text file and replaced the coded newlines with real newlines:
sed -i 's/ ~newline~ /\n/g' new.csv
References:
Ternary operator: https://stackoverflow.com/a/3953666/6316852
Count char occurrences: https://stackoverflow.com/a/41119233/6316852
Other peculiar cases: https://www.linuxquestions.org/questions/programming-9/complex-bash-string-substitution-of-csv-file-with-multiline-data-937179/
TL;DR
Run this:
i=0;cat file.csv|while read l;do i=$((($(echo $l|tr -cd '"'|wc -c)+$i)%2));[[ $i = 1 ]] && echo -n "$l " || echo "$l";done >new.csv
... and collect results in new.csv
I hope it helps!
If Perl is your option, please try the following:
perl -e '
while (<>) {
$str .= $_;
}
while ($str =~ /("(("")|[^"])*")|((^|(?<=,))[^,]*((?=,)|$))/g) {
if (($el = $&) =~ /^".*"$/s) {
$el =~ s/^"//s; $el =~ s/"$//s;
$el =~ s/""/"/g;
$el =~ s/\s+(?!$)/ /g;
}
push(#ary, $el);
}
foreach (#ary) {
print /\n$/ ? "$_" : "$_,";
}' sample.csv
sample.csv:
First name,Last name,Address,ZIP
John,Doe,"Country
City
Street",12345
John,Doe,"Country
City
Street",67890
Result:
First name,Last name,Address,ZIP
John,Doe,Country City Street,12345
John,Doe,Country City Street,67890
This might work for you (GNU sed):
sed ':a;s/[^,]\+/&/4;tb;N;ba;:b;s/\n\+/ /g;s/"//g' file
Test each line to see that it contains the correct number of fields (in the example that was 4). If there are not enough fields, append the next line and repeat the test. Otherwise, replace the newline(s) by spaces and finally remove the "'s.
N.B. This may be fraught with problems such as ,'s between "'s and quoted "'s.
Try cat -v file.csv. When the file was made with Excel, you might have some luck: When the newlines in a field are a simple \n and the newline at the end is a \r\n (which will look like ^M), parsing is simple.
# delete all newlines and replace the ^M with a new newline.
tr -d "\n" < file.csv| tr "\r" "\n"
# Above two steps with one command
tr "\n\r" " \n" < file.csv
When you want a space between the joined line, you need an additional step.
tr "\n\r" " \n" < file.csv | sed '2,$ s/^ //'
EDIT: #sjaak commented this didn't work is his case.
When your broken lines also have ^M you still can be a lucky (wo-)man.
When your broken field is always the first field in double quotes and you have GNU sed 4.2.2, you can join 2 lines when the first line has exactly one double quote.
sed -rz ':a;s/(\n|^)([^"]*)"([^"]*)\n/\1\2"\3 /;ta' file.csv
Explanation:
-z don't use \n as line endings
:a label for repeating the step after successful replacement
(\n|^) Search after a newline or the very first line
([^"]*) Substring without a "
ta Go back to label a and repeat
awk pattern matching is working.
answer in one line :
awk '/,"/{ORS=" "};/",/{ORS="\n"}{print $0}' YourFile
if you'd like to drop quotes, you could use:
awk '/,"/{ORS=" "};/",/{ORS="\n"}{print $0}' YourFile | sed 's/"//gw NewFile'
but I prefer to keep it.
to explain the code:
/Pattern/ : find pattern in current line.
ORS : indicates the output line record.
$0 : indicates the whole of the current line.
's/OldPattern/NewPattern/': substitude first OldPattern with NewPattern
/g : does the previous action for all OldPattern
/w : write the result to Newfile

shell: how to read a certain column in a certain line into a variable

I want to extract the first column of the last line of a text file. Instead of output the content of interest in another file and read it in again, can I just use some command to read it into a variable directly?
For exampole, if my file is like this:
...
123 456 789(this is the last line)
What I want is to read 123 into a variable in my shell script. How can I do that?
One approach is to extract the line you want, read its columns into an array, and emit the array element you want.
For the last line:
#!/bin/bash
# ^^^^- not /bin/sh, to enable arrays and process substitution
read -r -a columns < <(tail -n 1 "$filename") # put last line's columns into an array
echo "${columns[0]}" # emit the first column
Alternately, awk is an appropriate tool for the job:
line=2
column=1
var=$(awk -v line="$line" -v col="$column" 'NR == line { print $col }' <"$filename")
echo "Extracted the value: $var"
That said, if you're looking for a line close to the start of a file, it's often faster (in a runtime-performance sense) and easier to stick to shell builtins. For instance, to take the third column of the second line of a file:
{
read -r _ # throw away first line
read -r _ _ value _ # extract third value of second line
} <"$filename"
This works by using _s as placeholders for values you don't want to read.
I guess with "first column", you mean "first word", do you?
If it is guaranteed, that the last line doesn't start with a space, you can do
tail -n 1 YOUR_FILE | cut -d ' ' -f 1
You could also use sed:
$> var=$(sed -nr '$s/(^[^ ]*).*/\1/p' "file.txt")
The -nr tells sed to not output data by default (-n) and use extended regular expressions (-r to avoid needing to escape the paranthesis otherwise you have to write \( \))). The $ is an address that specifies the last line. The regular expression anchors the beginning of the line with the first ^, then matches everything that is not a space [^ ]* and puts that the result into a capture group ( ) and then gets rid of the rest of the line .* by replacing the line with the capture group \1, then print p to print the line.

Iterate over a file using two values on the same line

I need pass a series of couples values which are arguments for a c++ software. So I wrote this script:
while read randomNumbers; do
lambda = $randomNumbers | cut -f1 -d ' '
mi = $randomNumbers | cut -f2 -d ' '
./queueSim mm1-queue $lambda $mi
done < "randomNumbers"
where the first arg is the first value for each line in the file "randomNumbers" and the second one in the second value (of course). I got a segfault and a "command not found".
How can I assign to lambda and mi valus got from the line and pass this variable to c++ software?
There's no need for cut. Let read split the line for you:
while read lambda mi; do
./queueSim mm1-queue $lambda $mi
done < randomNumbers
Note that it is also commonly used in conjunction with IFS to split the input line on different fields. For example, to parse /etc/passwd ( a file with colon separated lines ), you will often see:
while IFS=: read username passwd uid gid info home shell; do ...
I would recommend assigning the values like this:
lambda=$(echo $randomNumbers | cut -f1 -d ' ')
mi=$(echo $randomNumbers | cut -f2 -d ' ')
the way you do it, you actually try to run a command that is named like whatever is the current content of $randomNumbers.
Edit:
Another thing: since your columns are delimited by a whitespace character, you could also just read the entire line into an array whose elements are separated by whitespaces as well. One way to achieve this is:
columns=( $(echo "$randomNumbers" | grep -o "[^ ]*") )
./queueSim mm1-queue ${columns[#]::2}
The first line matches all substrings that are not containing any spaces separately and puts them into the array columns. The second line does the same thing as the corresponding one in your implementation: inserting the first two columns as parameters. Since is done with slicing: you take the entire array ${columns[#]}, but select a certain subsequence of it by applying the boundary ::2 on the right, which returns in every element of columns beginning from the left (position 0), that is not on a position >=2.

Copy text from one line and create a new line with that next under it

I have a text file in which I want to find all of ID:= "abc123" when it finds that I want it to take that value of abc123 and create a new line and have a set string, newId:= "abc123 How can I do this within terminal?
I'd like to use bash, below are some examples, find the string '"ID": ", copy the value (abc123) and make a new line with this data.
"ID": "abc123"
"newID": "abc123"
You can do this:
sed -e 's/^"ID": "\(.*\)"/&\
"newID": "\1"/' myfile.txt
First, I'll try to explain the regular expression that searches for matches:
^ Matches the start of the line
"ID": " Matches that exact string
\(.*\) Matches a sequence of zero or more (*) of any character (.). Placing this expression between backslashed parenthesis creates a "capture", which allows us to store the resulting part of the match into an auxiliary variable \1.
" Matches the double-quote character
When it finds a match, it replaces it with:
& the match itself. This operator is an auxiliary variable that represents what was matched.
\<new-line> the backslash followed by an actual new line character escapes a new line, ie. it allows us to print a new line character into the replacement
"newId": " prints that exact string
\1 prints the contents of our capture, so it prints the ID we found
" prints a double quote character.
Hope this helps =)
Try doing this :
sed -r 's#^"ID": "([a-Z0-9]+)"#"newID": "\1"#' file.txt
sed : the executable
-r : extented mode (no need to backslash parenthesis)
s : we perform a substitution, skeleton is s#origin#replacement# (the separator can be anything)
^ : means start of line in regex
( ) : parenthesis is a capture
"newID": is the start of the new string
\1 : is the end of the substituted string (the captured string)
Considering your question is very vague I made some assumptions which will become apparent in my implementation.
INPUT FILE -- call it t
ID="one"
dkkd
ID="two"
ffkjf
ID="three"
ldl
Command ran on input file
for line in `cat t`; do newID=`echo $line | grep ID | cut -d= -f2`; if [[ "$newID" != "" ]]; then echo $line >> t2; echo newID=$newID >> t2; else echo $line >> t2; fi; done
OUTPUT FILE -- Name is t2 (apparent from the command)
ID="one"
newID="one"
dkkd
ID="two"
newID="two"
ffkjf
ID="three"
newID="three"
ldl
Basically this command goes line by line in the file (in this case called t) looks for an ID line. If it finds one it gets its value, prints the original line with the ID and then prints another one with a newID following right after. If the line in question does not have and ID then it just prints the line it self.
Things to note:
If you have any other line in the file that contains "ID" in it but is not the normal ID that you requested, this will not work.

Resources