For loop not working
1
I'm creating a bash script that among other things, checks a list against another list.
Basicly, I created this for loop to check the file "data.txt" for every item in "names.txt" And all matches should be output to "confirmed.txt" which, when finished, should be shown on screen. But for some reason, the file is always blank, am i missing somthing?
test
for code in data.txt
do
grep $code names.txt >> confirmed.txt
done
cat confirmed.txt
rm confirmed.txt
command-line bash scripts loop-device
asked Jan 6 at 20:13
Tech_PersonTech_Person
298
add a comment |
1
I'm creating a bash script that among other things, checks a list against another list.
Basicly, I created this for loop to check the file "data.txt" for every item in "names.txt" And all matches should be output to "confirmed.txt" which, when finished, should be shown on screen. But for some reason, the file is always blank, am i missing somthing?
test
for code in data.txt
do
grep $code names.txt >> confirmed.txt
done
cat confirmed.txt
rm confirmed.txt
command-line bash scripts loop-device
asked Jan 6 at 20:13
Tech_PersonTech_Person
298
If the items indata.txtare one-per-line, then you can skip the loop altogether and usegrep -f data.txt names.txtorgrep -Ff data.txt names.txtif you want them to be treated as fixed strings rather than basic regular expressions. (There's also no need to redirect the matching lines to a file that you're only going tocatonce and then delete.)
– steeldriver
Jan 6 at 21:59
add a comment |
1
1
1
I'm creating a bash script that among other things, checks a list against another list.
Basicly, I created this for loop to check the file "data.txt" for every item in "names.txt" And all matches should be output to "confirmed.txt" which, when finished, should be shown on screen. But for some reason, the file is always blank, am i missing somthing?
test
for code in data.txt
do
grep $code names.txt >> confirmed.txt
done
cat confirmed.txt
rm confirmed.txt
command-line bash scripts loop-device
asked Jan 6 at 20:13
Tech_PersonTech_Person
298
I'm creating a bash script that among other things, checks a list against another list.
Basicly, I created this for loop to check the file "data.txt" for every item in "names.txt" And all matches should be output to "confirmed.txt" which, when finished, should be shown on screen. But for some reason, the file is always blank, am i missing somthing?
test
for code in data.txt
do
grep $code names.txt >> confirmed.txt
done
cat confirmed.txt
rm confirmed.txt
command-line bash scripts loop-device
command-line bash scripts loop-device
asked Jan 6 at 20:13
Tech_PersonTech_Person
298
asked Jan 6 at 20:13
Tech_PersonTech_Person
298
asked Jan 6 at 20:13
Tech_PersonTech_Person
298
asked Jan 6 at 20:13
Tech_PersonTech_Person
298
asked Jan 6 at 20:13
Tech_PersonTech_Person
298
298
If the items indata.txtare one-per-line, then you can skip the loop altogether and usegrep -f data.txt names.txtorgrep -Ff data.txt names.txtif you want them to be treated as fixed strings rather than basic regular expressions. (There's also no need to redirect the matching lines to a file that you're only going tocatonce and then delete.)
– steeldriver
Jan 6 at 21:59
add a comment |
If the items indata.txtare one-per-line, then you can skip the loop altogether and usegrep -f data.txt names.txtorgrep -Ff data.txt names.txtif you want them to be treated as fixed strings rather than basic regular expressions. (There's also no need to redirect the matching lines to a file that you're only going tocatonce and then delete.)
– steeldriver
Jan 6 at 21:59
If the items in
data.txt are one-per-line, then you can skip the loop altogether and use grep -f data.txt names.txt or grep -Ff data.txt names.txt if you want them to be treated as fixed strings rather than basic regular expressions. (There's also no need to redirect the matching lines to a file that you're only going to cat once and then delete.)– steeldriver
Jan 6 at 21:59
If the items in
data.txt are one-per-line, then you can skip the loop altogether and use grep -f data.txt names.txt or grep -Ff data.txt names.txt if you want them to be treated as fixed strings rather than basic regular expressions. (There's also no need to redirect the matching lines to a file that you're only going to cat once and then delete.)– steeldriver
Jan 6 at 21:59
add a comment |
1 Answer
1
active
oldest
votes
2
for code in `cat data.txt`
do
grep $code names.txt >> confirmed.txt
done
cat confirmed.txt
rm confirmed.txt
answered Jan 6 at 20:23
VijayVijay
1,5811618
I'm unsure why this worked and my set didn't, but thank you
– Tech_Person
Jan 6 at 20:26
for code in data.txt, $code isdata.txt. Becausefordoes not read the filedata.txt.data.txtis just a word/string. `cat data.txt` makes it read the file.
– Vijay
Jan 6 at 20:46
ok, Thankyou @Vijay
– Tech_Person
Jan 6 at 23:29
add a comment |
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1 Answer
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1 Answer
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2
for code in `cat data.txt`
do
grep $code names.txt >> confirmed.txt
done
cat confirmed.txt
rm confirmed.txt
answered Jan 6 at 20:23
VijayVijay
1,5811618
I'm unsure why this worked and my set didn't, but thank you
– Tech_Person
Jan 6 at 20:26
for code in data.txt, $code isdata.txt. Becausefordoes not read the filedata.txt.data.txtis just a word/string. `cat data.txt` makes it read the file.
– Vijay
Jan 6 at 20:46
ok, Thankyou @Vijay
– Tech_Person
Jan 6 at 23:29
add a comment |
2
for code in `cat data.txt`
do
grep $code names.txt >> confirmed.txt
done
cat confirmed.txt
rm confirmed.txt
answered Jan 6 at 20:23
VijayVijay
1,5811618
I'm unsure why this worked and my set didn't, but thank you
– Tech_Person
Jan 6 at 20:26
for code in data.txt, $code isdata.txt. Becausefordoes not read the filedata.txt.data.txtis just a word/string. `cat data.txt` makes it read the file.
– Vijay
Jan 6 at 20:46
ok, Thankyou @Vijay
– Tech_Person
Jan 6 at 23:29
add a comment |
2
2
2
for code in `cat data.txt`
do
grep $code names.txt >> confirmed.txt
done
cat confirmed.txt
rm confirmed.txt
answered Jan 6 at 20:23
VijayVijay
1,5811618
for code in `cat data.txt`
do
grep $code names.txt >> confirmed.txt
done
cat confirmed.txt
rm confirmed.txt
answered Jan 6 at 20:23
VijayVijay
1,5811618
answered Jan 6 at 20:23
VijayVijay
1,5811618
answered Jan 6 at 20:23
VijayVijay
1,5811618
answered Jan 6 at 20:23
VijayVijay
1,5811618
1,5811618
I'm unsure why this worked and my set didn't, but thank you
– Tech_Person
Jan 6 at 20:26
for code in data.txt, $code isdata.txt. Becausefordoes not read the filedata.txt.data.txtis just a word/string. `cat data.txt` makes it read the file.
– Vijay
Jan 6 at 20:46
ok, Thankyou @Vijay
– Tech_Person
Jan 6 at 23:29
add a comment |
I'm unsure why this worked and my set didn't, but thank you
– Tech_Person
Jan 6 at 20:26
for code in data.txt, $code isdata.txt. Becausefordoes not read the filedata.txt.data.txtis just a word/string. `cat data.txt` makes it read the file.
– Vijay
Jan 6 at 20:46
ok, Thankyou @Vijay
– Tech_Person
Jan 6 at 23:29
I'm unsure why this worked and my set didn't, but thank you
– Tech_Person
Jan 6 at 20:26
I'm unsure why this worked and my set didn't, but thank you
– Tech_Person
Jan 6 at 20:26
for code in data.txt, $code is data.txt. Because for does not read the file data.txt. data.txt is just a word/string. `cat data.txt` makes it read the file.– Vijay
Jan 6 at 20:46
for code in data.txt, $code is data.txt. Because for does not read the file data.txt. data.txt is just a word/string. `cat data.txt` makes it read the file.– Vijay
Jan 6 at 20:46
ok, Thankyou @Vijay
– Tech_Person
Jan 6 at 23:29
ok, Thankyou @Vijay
– Tech_Person
Jan 6 at 23:29
add a comment |
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If the items in
data.txtare one-per-line, then you can skip the loop altogether and usegrep -f data.txt names.txtorgrep -Ff data.txt names.txtif you want them to be treated as fixed strings rather than basic regular expressions. (There's also no need to redirect the matching lines to a file that you're only going tocatonce and then delete.)– steeldriver
Jan 6 at 21:59