How can I write a linux command to delete the last column of tab-delimited csv?
Example input
aaa bbb ccc ddd
111 222 333 444
Expected output
aaa bbb ccc
111 222 333
It is easy to remove the fist field instead of the last. So we reverse the content, remove the first field, and then revers it again.
Here is an example for a "CSV"
rev file1 | cut -d "," -f 2- | rev
Replace the "file1" and the "," with your file name and the delimiter accordingly.
You can use cut for this. You specify a delimiter with option -d and then give the field numbers (option -f) you want to have in the output. Each line of the input gets treated individually:
cut -d$'\t' -f 1-6 < my.csv > new.csv
This is according to your words. Your example looks more like you want to strip a column in the middle:
cut -d$'\t' -f 1-3,5-7 < my.csv > new.csv
The $'\t' is a bash notation for the string containing the single tab character.
You can use below command which will delete the last column of tab-delimited csv irrespective of field numbers,
sed -r 's/(.*)\s+[^\s]+$/\1/'
for example:
echo "aaa bbb ccc ddd 111 222 333 444" | sed -r 's/(.*)\s+[^\s]+$/\1/'
Related
Is it possible to remove multiple spaces from a text file and save the changes in the same file using awk or grep?
Input example:
aaa bbb ccc
ddd yyyy
Output I want:
aaa bbb ccc
ddd yyyy
Simply reset value of $1 to again $1 which will allow OFS to come into picture and will add proper spaces into lines.
awk '{$1=$1} 1' Input_file
EDIT: Since OP mentioned that what if we want to keep only starting spaces then try following.
awk '
match($0,/^ +/){
spaces=substr($0,RSTART,RLENGTH)
}
{
$1=$1
$1=spaces $1
spaces=""
}
1
' Input_file
Using sed
sed -i -E 's#[[:space:]]+# #g' < input file
For removing spaces at the start
sed -i -E 's#[[:space:]]+# #g; s#^ ##g' < input file
Demo:
$cat test.txt
aaa bbb ccc
ddd yyyy
Output I want:
aaa bbb ccc
ddd yyyy
$sed -i -E 's#[[:space:]]+# #g' test.txt
$cat test.txt
aaa bbb ccc
ddd yyyy
Output I want:
aaa bbb ccc
ddd yyyy
$
I have a file which looks like:
AA
2
3
4
CCC
111
222
333
XXX
12
23
34
I am looking for awk command to search for a string 'CCC' from above and print all the lines that occur after 'CCC' but stop reading as soon as i reach 'XXX'.
A very simple command does the read for me but does not stop at XXX.
awk '$0 == "CCC" {i=1;next};i && i++' c.out
Could you please try following.
Solution 1st: With sed.
sed -n '/CCC/,/XXX/p' Input_file
Solution 2nd: With awk.
awk '/CCC/{flag=1} flag; /XXX/{flag=""}' Input_file
Solution 3rd: In case you want to print from string CCC to XXX but not these strings then do following.
awk '/CCC/{flag=1;next} /XXX/{flag=""} flag' Input_file
"Do something between this and that" can easily be solved with a range pattern:
awk '/CCC/,/XXX/' # prints everything between CCC and XXX (inclusive)
But it's not exactly what you've asked. You wanted to print everything after CCC and quit (stop reading) on XXX. This translates to
awk '/XXX/{exit};f;/CCC/{f=1}'
Let's say I have:
file1.tsv
Foo\tBar\tabc\t123
Bla\tWord\tabc\tqwer
Blub\tqwe\tasd\tqqq
file2.tsv
123\tzxcv\tAAA\tqaa
asd\t999\tBBB\tdef
qwe\t111\tCCC\tabc
And I want to overwrite column 3 of file1.tsv with column 3 of file2.tsv to end up with:
Foo\tBar\tAAA\t123
Bla\tWord\tBBB\tqwer
Blub\tqwe\tCCC\tqqq
What would be a good way to do this in bash?
Take a look at this awk:
awk 'FNR==NR{a[NR]=$3;next}{$3=a[FNR]}1' OFS='\t' file{2,1}.tsv > output.tsv
If you want to use just bash, with little more effort:
while IFS=$'\t' read -r a1 a2 _ a4; do
IFS=$'\t' read -ru3 _ _ b3 _
printf '%s\t%s\t%s\t%s\n' "$a1" "$a2" "$b3" "$a4"
done <file1.tsv 3<file2.tsv >output.tsv
Output:
Foo Bar AAA 123
Bla Word BBB qwer
Blub qwe CCC qqq
Another way to do this can be, with correction as pointed out by #PesaThe:
paste -d$'\t' <(cut -d$'\t' -f1,2 file1.tsv) <(cut -d$'\t' -f3 file2.tsv) <(cut -d$'\t' -f4 file1.tsv)
The output will be:
Foo Bar AAA 123
Bla Word BBB qwer
Blub qwe CCC qqq
I have a requirement to convert a delimited file to fixed-width file, details as follows.
Input file sample:
AAA|BBB|C|1234|56
AA1|BB2|DD|12345|890
Output file sample:
AAA BBB C 1234 56
AA1 BB2 DD 12345 890
Details of field positions
Field 1 Start at position 1 and length should be 5
Field 2 start at position 6 and length should be 6
Field 3 Start at position 12 and length should be 4
Field 4 Start at position 16 and length should be 6
Field 5 Start at position 22 and length should be 3
Another awk solution:
echo -e "AAA|BBB|C|1234|56\nAA1|BB2|DD|12345|890" |
awk -F '|' '{printf "%-5s%-6s%-4s%-6s%-3s\n",$1,$2,$3,$4,$5}'
Note the - before the %-3s in the printf statement, which will left-align the fields, as required in the question. Output:
AAA BBB C 1234 56
AA1 BB2 DD 12345 890
With the following awk command you can achive your goal:
awk 'BEGIN { RS=" "; FS="|" } { printf "%5s%6s%4s%6s%3s\n",$1,$2,$3,$4,$5 }' your_input_file
Your record separator (RS) is a space and your field separator (FS) is a pipe (|) character. In order to parse your data correctly we set them in the BEGIN statement (before any data is read). Then using printf and the desired format characters we output the data in the desired format.
Output:
AAA BBB C 1234 56
AA1 BB2 DD 12345890
Update:
I just saw your edits on the input file format (previously they seemed different). If your input data records are separated with a new line then simply remove the RS=" "; part from the above one-liner and apply the - modifiers for the format characters to left align your fields:
awk 'BEGIN { FS="|" } { printf "%-5s%-6s%-4s%-6s%-3s\n",$1,$2,$3,$4,$5 }' your_input_file
Suppose I have a file info.txt. The first column is the id, and the rest are its content.
1 aaa bbb
1 ccc ddd mmm
4 ccc eee
7 ddd fff jjj kkk
I'm only intereted with the lines beginning with "1". So I use grep to filter it:
what_I_concern=$(cat info.txt | grep -iw 1 | cut -d ' ' -f 2-)
and then I want to iterate through these lines:
for i in $what_I_concern; do
pass $i to another program #I want to pass one line at a time
done
But what it really did is to iterate through every word in these lines, instead of taking each line as a whole.
How can I solve this problem?
The way you're trying to accomplish what you need is causing word splitting. Instead, say:
while read -r line; do
someprogram $(cut -d' ' -f2- <<< "$line")
done < <(grep '^1' info.txt)
The <() syntax is known as Process Substitution. In this case, it enables the while loop to read the output of the grep command as a file.
You can avoid using grep and cut altogether in this case (assuming default IFS)
while read -r first rest; do
[ "$first" = "1" ] && pass "$rest" to another program;
done < info.txt