please explain below command Announcing the arrival of Valued Associate #679: Cesar Manara Planned maintenance scheduled April 17/18, 2019 at 00:00UTC (8:00pm US/Eastern) 2019 Community Moderator Election Results Why I closed the “Why is Kali so hard” questionStruggles with grep, sed, awk to filter htmlPlease help explain this bash output redirectionPlease explain the Awk script provided belowExplain the shell command: shift $(($optind - 1))Please explain this awk statementCan someome explain me the below awk substring command val=$( echo $text $len|awk 'print substr($0,0,$2)')Please explain below bash functionCan someone please explain the meaning of the following awk script?Please explain what does exec, trap, mknod, tee doCan someone explain this line of code/command please?
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please explain below command
Announcing the arrival of Valued Associate #679: Cesar Manara
Planned maintenance scheduled April 17/18, 2019 at 00:00UTC (8:00pm US/Eastern)
2019 Community Moderator Election Results
Why I closed the “Why is Kali so hard” questionStruggles with grep, sed, awk to filter htmlPlease help explain this bash output redirectionPlease explain the Awk script provided belowExplain the shell command: shift $(($optind - 1))Please explain this awk statementCan someome explain me the below awk substring command val=$( echo $text $len|awk 'print substr($0,0,$2)')Please explain below bash functionCan someone please explain the meaning of the following awk script?Please explain what does exec, trap, mknod, tee doCan someone explain this line of code/command please?
.everyoneloves__top-leaderboard:empty,.everyoneloves__mid-leaderboard:empty,.everyoneloves__bot-mid-leaderboard:empty margin-bottom:0;
getDateFormat() awk -F"_" 'print $1'
I would like to know What does the above function do?
$ awk '$2 == "1" print $0 ' cols.txt
Where the match occurs, print the entire line. But what this command returns
echo $1 | awk -F"-" 'print $2'
$ii - What is this?
i=1;
echo $ii
It didn't print anything.
shell-script shell awk variable
edited Apr 13 at 15:00
Rui F Ribeiro
42.1k1484142
asked Jun 16 '17 at 14:41
Shivashankari SekarShivashankari Sekar
12
add a comment |
getDateFormat() awk -F"_" 'print $1'
I would like to know What does the above function do?
$ awk '$2 == "1" print $0 ' cols.txt
Where the match occurs, print the entire line. But what this command returns
echo $1 | awk -F"-" 'print $2'
$ii - What is this?
i=1;
echo $ii
It didn't print anything.
shell-script shell awk variable
edited Apr 13 at 15:00
Rui F Ribeiro
42.1k1484142
asked Jun 16 '17 at 14:41
Shivashankari SekarShivashankari Sekar
12
5
One cannot explain this abomination of code. From uninitialized variables ($iiused in a test) to inconsistent spelling and capitalization of the months, to an undocumented and clearly uncommon input requirement.
– KevinO
Jun 16 '17 at 15:27
add a comment |
getDateFormat() awk -F"_" 'print $1'
I would like to know What does the above function do?
$ awk '$2 == "1" print $0 ' cols.txt
Where the match occurs, print the entire line. But what this command returns
echo $1 | awk -F"-" 'print $2'
$ii - What is this?
i=1;
echo $ii
It didn't print anything.
shell-script shell awk variable
edited Apr 13 at 15:00
Rui F Ribeiro
42.1k1484142
asked Jun 16 '17 at 14:41
Shivashankari SekarShivashankari Sekar
12
getDateFormat() awk -F"_" 'print $1'
I would like to know What does the above function do?
$ awk '$2 == "1" print $0 ' cols.txt
Where the match occurs, print the entire line. But what this command returns
echo $1 | awk -F"-" 'print $2'
$ii - What is this?
i=1;
echo $ii
It didn't print anything.
shell-script shell awk variable
shell-script shell awk variable
edited Apr 13 at 15:00
Rui F Ribeiro
42.1k1484142
asked Jun 16 '17 at 14:41
Shivashankari SekarShivashankari Sekar
12
edited Apr 13 at 15:00
Rui F Ribeiro
42.1k1484142
asked Jun 16 '17 at 14:41
Shivashankari SekarShivashankari Sekar
12
edited Apr 13 at 15:00
Rui F Ribeiro
42.1k1484142
edited Apr 13 at 15:00
Rui F Ribeiro
42.1k1484142
edited Apr 13 at 15:00
Rui F Ribeiro
42.1k1484142
42.1k1484142
asked Jun 16 '17 at 14:41
Shivashankari SekarShivashankari Sekar
12
asked Jun 16 '17 at 14:41
Shivashankari SekarShivashankari Sekar
12
asked Jun 16 '17 at 14:41
Shivashankari SekarShivashankari Sekar
12
12
5
One cannot explain this abomination of code. From uninitialized variables ($iiused in a test) to inconsistent spelling and capitalization of the months, to an undocumented and clearly uncommon input requirement.
– KevinO
Jun 16 '17 at 15:27
add a comment |
5
One cannot explain this abomination of code. From uninitialized variables ($iiused in a test) to inconsistent spelling and capitalization of the months, to an undocumented and clearly uncommon input requirement.
– KevinO
Jun 16 '17 at 15:27
5
5
One cannot explain this abomination of code. From uninitialized variables (
$ii used in a test) to inconsistent spelling and capitalization of the months, to an undocumented and clearly uncommon input requirement.– KevinO
Jun 16 '17 at 15:27
One cannot explain this abomination of code. From uninitialized variables (
$ii used in a test) to inconsistent spelling and capitalization of the months, to an undocumented and clearly uncommon input requirement.– KevinO
Jun 16 '17 at 15:27
add a comment |
1 Answer
1
active
oldest
votes
$1 is the first positional parameter, i.e. argument to the function. awk -F- sets awks field separator to a dash, and print $2 prints the second field. So from aa-bb-cc, you'd get bb.
Presumably the function expects to be called as getDateFormat something-2017-06 which looks odd, but the year is picked from the second dash-separated field.
$ii would refer to a variable, but it's not set before the test if [ $mm -eq $ii ]; so the test sees [ 123 -eq ] (with 123 probably some number picked from $1). That causes an error since the operator -eq is missing the other operand.
answered Jun 16 '17 at 15:21
ilkkachuilkkachu
63.5k10104181
iiis undefined on the first iteration, but that's semantically zero; on subsequent iterations, it gets incremented. I don't think the logic is entirely correct, but with a few fixes, the loop would convert -- horribly clumsily -- from a month name to a month number. (Notice also how the month names use erratic capitalization and abbreviation conventions, and how July is incorrectly listed before June.)
– tripleee
Jun 16 '17 at 15:43
I guess withii=1instead ofi=1it would superficially work for many month names.
– tripleee
Jun 16 '17 at 15:47
mmis set before the loop, apparently to the month name.
– tripleee
Jun 16 '17 at 15:47
@tripleee, without changing fromi=1toii=1, I get an error in bash on the first loop, so I think it needs to be set prior to the first loop iteration as you subsequently noted.
– KevinO
Jun 16 '17 at 15:56
@tripleee, sorry, my bad on themm. But since$iiis unquoted, it resolves to nothing, so that still doesn't work... And even when quoted, I think the empty string would give an error from-eq.
– ilkkachu
Jun 16 '17 at 16:16
|
show 3 more comments
Your Answer
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1 Answer
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1 Answer
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oldest
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oldest
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oldest
votes
$1 is the first positional parameter, i.e. argument to the function. awk -F- sets awks field separator to a dash, and print $2 prints the second field. So from aa-bb-cc, you'd get bb.
Presumably the function expects to be called as getDateFormat something-2017-06 which looks odd, but the year is picked from the second dash-separated field.
$ii would refer to a variable, but it's not set before the test if [ $mm -eq $ii ]; so the test sees [ 123 -eq ] (with 123 probably some number picked from $1). That causes an error since the operator -eq is missing the other operand.
answered Jun 16 '17 at 15:21
ilkkachuilkkachu
63.5k10104181
iiis undefined on the first iteration, but that's semantically zero; on subsequent iterations, it gets incremented. I don't think the logic is entirely correct, but with a few fixes, the loop would convert -- horribly clumsily -- from a month name to a month number. (Notice also how the month names use erratic capitalization and abbreviation conventions, and how July is incorrectly listed before June.)
– tripleee
Jun 16 '17 at 15:43
I guess withii=1instead ofi=1it would superficially work for many month names.
– tripleee
Jun 16 '17 at 15:47
mmis set before the loop, apparently to the month name.
– tripleee
Jun 16 '17 at 15:47
@tripleee, without changing fromi=1toii=1, I get an error in bash on the first loop, so I think it needs to be set prior to the first loop iteration as you subsequently noted.
– KevinO
Jun 16 '17 at 15:56
@tripleee, sorry, my bad on themm. But since$iiis unquoted, it resolves to nothing, so that still doesn't work... And even when quoted, I think the empty string would give an error from-eq.
– ilkkachu
Jun 16 '17 at 16:16
|
show 3 more comments
$1 is the first positional parameter, i.e. argument to the function. awk -F- sets awks field separator to a dash, and print $2 prints the second field. So from aa-bb-cc, you'd get bb.
Presumably the function expects to be called as getDateFormat something-2017-06 which looks odd, but the year is picked from the second dash-separated field.
$ii would refer to a variable, but it's not set before the test if [ $mm -eq $ii ]; so the test sees [ 123 -eq ] (with 123 probably some number picked from $1). That causes an error since the operator -eq is missing the other operand.
answered Jun 16 '17 at 15:21
ilkkachuilkkachu
63.5k10104181
iiis undefined on the first iteration, but that's semantically zero; on subsequent iterations, it gets incremented. I don't think the logic is entirely correct, but with a few fixes, the loop would convert -- horribly clumsily -- from a month name to a month number. (Notice also how the month names use erratic capitalization and abbreviation conventions, and how July is incorrectly listed before June.)
– tripleee
Jun 16 '17 at 15:43
I guess withii=1instead ofi=1it would superficially work for many month names.
– tripleee
Jun 16 '17 at 15:47
mmis set before the loop, apparently to the month name.
– tripleee
Jun 16 '17 at 15:47
@tripleee, without changing fromi=1toii=1, I get an error in bash on the first loop, so I think it needs to be set prior to the first loop iteration as you subsequently noted.
– KevinO
Jun 16 '17 at 15:56
@tripleee, sorry, my bad on themm. But since$iiis unquoted, it resolves to nothing, so that still doesn't work... And even when quoted, I think the empty string would give an error from-eq.
– ilkkachu
Jun 16 '17 at 16:16
|
show 3 more comments
$1 is the first positional parameter, i.e. argument to the function. awk -F- sets awks field separator to a dash, and print $2 prints the second field. So from aa-bb-cc, you'd get bb.
Presumably the function expects to be called as getDateFormat something-2017-06 which looks odd, but the year is picked from the second dash-separated field.
$ii would refer to a variable, but it's not set before the test if [ $mm -eq $ii ]; so the test sees [ 123 -eq ] (with 123 probably some number picked from $1). That causes an error since the operator -eq is missing the other operand.
answered Jun 16 '17 at 15:21
ilkkachuilkkachu
63.5k10104181
$1 is the first positional parameter, i.e. argument to the function. awk -F- sets awks field separator to a dash, and print $2 prints the second field. So from aa-bb-cc, you'd get bb.
Presumably the function expects to be called as getDateFormat something-2017-06 which looks odd, but the year is picked from the second dash-separated field.
$ii would refer to a variable, but it's not set before the test if [ $mm -eq $ii ]; so the test sees [ 123 -eq ] (with 123 probably some number picked from $1). That causes an error since the operator -eq is missing the other operand.
answered Jun 16 '17 at 15:21
ilkkachuilkkachu
63.5k10104181
edited Jun 16 '17 at 16:12
answered Jun 16 '17 at 15:21
ilkkachuilkkachu
63.5k10104181
answered Jun 16 '17 at 15:21
ilkkachuilkkachu
63.5k10104181
answered Jun 16 '17 at 15:21
ilkkachuilkkachu
63.5k10104181
63.5k10104181
iiis undefined on the first iteration, but that's semantically zero; on subsequent iterations, it gets incremented. I don't think the logic is entirely correct, but with a few fixes, the loop would convert -- horribly clumsily -- from a month name to a month number. (Notice also how the month names use erratic capitalization and abbreviation conventions, and how July is incorrectly listed before June.)
– tripleee
Jun 16 '17 at 15:43
I guess withii=1instead ofi=1it would superficially work for many month names.
– tripleee
Jun 16 '17 at 15:47
mmis set before the loop, apparently to the month name.
– tripleee
Jun 16 '17 at 15:47
@tripleee, without changing fromi=1toii=1, I get an error in bash on the first loop, so I think it needs to be set prior to the first loop iteration as you subsequently noted.
– KevinO
Jun 16 '17 at 15:56
@tripleee, sorry, my bad on themm. But since$iiis unquoted, it resolves to nothing, so that still doesn't work... And even when quoted, I think the empty string would give an error from-eq.
– ilkkachu
Jun 16 '17 at 16:16
|
show 3 more comments
iiis undefined on the first iteration, but that's semantically zero; on subsequent iterations, it gets incremented. I don't think the logic is entirely correct, but with a few fixes, the loop would convert -- horribly clumsily -- from a month name to a month number. (Notice also how the month names use erratic capitalization and abbreviation conventions, and how July is incorrectly listed before June.)
– tripleee
Jun 16 '17 at 15:43
I guess withii=1instead ofi=1it would superficially work for many month names.
– tripleee
Jun 16 '17 at 15:47
mmis set before the loop, apparently to the month name.
– tripleee
Jun 16 '17 at 15:47
@tripleee, without changing fromi=1toii=1, I get an error in bash on the first loop, so I think it needs to be set prior to the first loop iteration as you subsequently noted.
– KevinO
Jun 16 '17 at 15:56
@tripleee, sorry, my bad on themm. But since$iiis unquoted, it resolves to nothing, so that still doesn't work... And even when quoted, I think the empty string would give an error from-eq.
– ilkkachu
Jun 16 '17 at 16:16
ii is undefined on the first iteration, but that's semantically zero; on subsequent iterations, it gets incremented. I don't think the logic is entirely correct, but with a few fixes, the loop would convert -- horribly clumsily -- from a month name to a month number. (Notice also how the month names use erratic capitalization and abbreviation conventions, and how July is incorrectly listed before June.)– tripleee
Jun 16 '17 at 15:43
ii is undefined on the first iteration, but that's semantically zero; on subsequent iterations, it gets incremented. I don't think the logic is entirely correct, but with a few fixes, the loop would convert -- horribly clumsily -- from a month name to a month number. (Notice also how the month names use erratic capitalization and abbreviation conventions, and how July is incorrectly listed before June.)– tripleee
Jun 16 '17 at 15:43
I guess with
ii=1 instead of i=1 it would superficially work for many month names.– tripleee
Jun 16 '17 at 15:47
I guess with
ii=1 instead of i=1 it would superficially work for many month names.– tripleee
Jun 16 '17 at 15:47
mm is set before the loop, apparently to the month name.– tripleee
Jun 16 '17 at 15:47
mm is set before the loop, apparently to the month name.– tripleee
Jun 16 '17 at 15:47
@tripleee, without changing from
i=1 to ii=1, I get an error in bash on the first loop, so I think it needs to be set prior to the first loop iteration as you subsequently noted.– KevinO
Jun 16 '17 at 15:56
@tripleee, without changing from
i=1 to ii=1, I get an error in bash on the first loop, so I think it needs to be set prior to the first loop iteration as you subsequently noted.– KevinO
Jun 16 '17 at 15:56
@tripleee, sorry, my bad on the
mm. But since $ii is unquoted, it resolves to nothing, so that still doesn't work... And even when quoted, I think the empty string would give an error from -eq.– ilkkachu
Jun 16 '17 at 16:16
@tripleee, sorry, my bad on the
mm. But since $ii is unquoted, it resolves to nothing, so that still doesn't work... And even when quoted, I think the empty string would give an error from -eq.– ilkkachu
Jun 16 '17 at 16:16
|
show 3 more comments
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5
One cannot explain this abomination of code. From uninitialized variables (
$iiused in a test) to inconsistent spelling and capitalization of the months, to an undocumented and clearly uncommon input requirement.– KevinO
Jun 16 '17 at 15:27