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.everyoneloves__top-leaderboard:empty,.everyoneloves__mid-leaderboard:empty,.everyoneloves__bot-mid-leaderboard:empty{ margin-bottom:0;
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1

I have this awk command:

awk -F, 'NR==FNR{_1[$1]++;next}_1[$1]' file1 file2

I actually almost know what the program is doing, but I don't know what _1 means. The intention is to compare two files, one has 1 field and the other has 4 fields.

Here's what I'm trying to do. I have these files, I need to know which numbers on file1 is in file 2 and then print the record of file 2.

file1

89611862

89613696

84126597

88690669

60147342

file2

84126597,12345300943529348333,2805058C30730000,28

88767631,12345712012010684248,2805058C30730002,28

83218719,12345712012012622594,2805058C30730006,28

89611862,12345712012010174449,2805058C30730014,28

85933710,12345712012007778032,2805058C3073001A,26

88690669,12345712012012060159,2805058C3073001E,28

60147342,12345712012011235922,2805058C30730030,28

89613696,12345712012008043980,2805058C3073003C,28

84783612,12345712012031117926,2805058C3073004C,28

awk -F, 'NR==FNR{arr[$1]++;next}arr[$1]' file1 file2

But it only prints the last found record:

60147342,12345712012011235922,2805058C30730030,28 

Thanks!

awk

share|improve this question

edited 1 hour ago

Kusalananda♦

140k17261435

asked 2 hours ago

Chila MendezChila Mendez

83

New contributor

Chila Mendez is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  take care with the line terminators; some lines from file1 may be terminated by cr/lf, windows-mode. Do you have the same problem if you replace -F, with -F'[,r]'?
  
  – mosvy
  1 hour ago
  
  
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  You are absolutely right!! I change it and it works, and yes, I have that problem with the file1. Thanks!!
  
  – Chila Mendez
  1 hour ago
  

  
  
  
  

add a comment | 

1

I have this awk command:

awk -F, 'NR==FNR{_1[$1]++;next}_1[$1]' file1 file2

I actually almost know what the program is doing, but I don't know what _1 means. The intention is to compare two files, one has 1 field and the other has 4 fields.

Here's what I'm trying to do. I have these files, I need to know which numbers on file1 is in file 2 and then print the record of file 2.

file1

89611862

89613696

84126597

88690669

60147342

file2

84126597,12345300943529348333,2805058C30730000,28

88767631,12345712012010684248,2805058C30730002,28

83218719,12345712012012622594,2805058C30730006,28

89611862,12345712012010174449,2805058C30730014,28

85933710,12345712012007778032,2805058C3073001A,26

88690669,12345712012012060159,2805058C3073001E,28

60147342,12345712012011235922,2805058C30730030,28

89613696,12345712012008043980,2805058C3073003C,28

84783612,12345712012031117926,2805058C3073004C,28

awk -F, 'NR==FNR{arr[$1]++;next}arr[$1]' file1 file2

But it only prints the last found record:

60147342,12345712012011235922,2805058C30730030,28 

Thanks!

awk

share|improve this question

edited 1 hour ago

Kusalananda♦

140k17261435

asked 2 hours ago

Chila MendezChila Mendez

83

New contributor

Chila Mendez is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  take care with the line terminators; some lines from file1 may be terminated by cr/lf, windows-mode. Do you have the same problem if you replace -F, with -F'[,r]'?
  
  – mosvy
  1 hour ago
  
  
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  You are absolutely right!! I change it and it works, and yes, I have that problem with the file1. Thanks!!
  
  – Chila Mendez
  1 hour ago
  

  
  
  
  

add a comment | 

I have this awk command:

awk -F, 'NR==FNR{_1[$1]++;next}_1[$1]' file1 file2

I actually almost know what the program is doing, but I don't know what _1 means. The intention is to compare two files, one has 1 field and the other has 4 fields.

Here's what I'm trying to do. I have these files, I need to know which numbers on file1 is in file 2 and then print the record of file 2.

file1

89611862

89613696

84126597

88690669

60147342

file2

84126597,12345300943529348333,2805058C30730000,28

88767631,12345712012010684248,2805058C30730002,28

83218719,12345712012012622594,2805058C30730006,28

89611862,12345712012010174449,2805058C30730014,28

85933710,12345712012007778032,2805058C3073001A,26

88690669,12345712012012060159,2805058C3073001E,28

60147342,12345712012011235922,2805058C30730030,28

89613696,12345712012008043980,2805058C3073003C,28

84783612,12345712012031117926,2805058C3073004C,28

awk -F, 'NR==FNR{arr[$1]++;next}arr[$1]' file1 file2

But it only prints the last found record:

60147342,12345712012011235922,2805058C30730030,28 

Thanks!

awk

share|improve this question

edited 1 hour ago

Kusalananda♦

140k17261435

asked 2 hours ago

Chila MendezChila Mendez

83

New contributor

Chila Mendez is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

awk -F, 'NR==FNR{_1[$1]++;next}_1[$1]' file1 file2

89611862

89613696

84126597

88690669

60147342

84126597,12345300943529348333,2805058C30730000,28

88767631,12345712012010684248,2805058C30730002,28

83218719,12345712012012622594,2805058C30730006,28

89611862,12345712012010174449,2805058C30730014,28

85933710,12345712012007778032,2805058C3073001A,26

88690669,12345712012012060159,2805058C3073001E,28

60147342,12345712012011235922,2805058C30730030,28

89613696,12345712012008043980,2805058C3073003C,28

84783612,12345712012031117926,2805058C3073004C,28

awk -F, 'NR==FNR{arr[$1]++;next}arr[$1]' file1 file2

60147342,12345712012011235922,2805058C30730030,28 

share|improve this question

edited 1 hour ago

Kusalananda♦

140k17261435

asked 2 hours ago

Chila MendezChila Mendez

83

New contributor

Chila Mendez is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

share|improve this question

edited 1 hour ago

Kusalananda♦

140k17261435

asked 2 hours ago

Chila MendezChila Mendez

83

New contributor

Chila Mendez is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

edited 1 hour ago

Kusalananda♦

140k17261435

edited 1 hour ago

Kusalananda♦

140k17261435

asked 2 hours ago

Chila MendezChila Mendez

83

New contributor

Chila Mendez is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

asked 2 hours ago

Chila MendezChila Mendez

83

1 Answer
1

active

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2

awk does not allow digit-only variable names (and variable names can't begin with a digit as well), so _1 is a trick to prepend _ in front of 1; so, _1 is a variable name in your awk program, which happens to be an array in this case.

Here is an example:

% awk 'BEGIN {1 = 3}'

awk: cmd. line:1: BEGIN {1 = 3}

awk: cmd. line:1:          ^ syntax error



% awk 'BEGIN {_1 = 3}'  # runs fine

---

As an aside, you should use readable variable names in your program to have better maintainability unless you're golfing intentionally.

share|improve this answer

answered 2 hours ago

heemaylheemayl

36.2k378108

add a comment | 

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2

awk does not allow digit-only variable names (and variable names can't begin with a digit as well), so _1 is a trick to prepend _ in front of 1; so, _1 is a variable name in your awk program, which happens to be an array in this case.

Here is an example:

% awk 'BEGIN {1 = 3}'

awk: cmd. line:1: BEGIN {1 = 3}

awk: cmd. line:1:          ^ syntax error



% awk 'BEGIN {_1 = 3}'  # runs fine

---

As an aside, you should use readable variable names in your program to have better maintainability unless you're golfing intentionally.

share|improve this answer

answered 2 hours ago

heemaylheemayl

36.2k378108

add a comment | 

2

awk does not allow digit-only variable names (and variable names can't begin with a digit as well), so _1 is a trick to prepend _ in front of 1; so, _1 is a variable name in your awk program, which happens to be an array in this case.

Here is an example:

% awk 'BEGIN {1 = 3}'

awk: cmd. line:1: BEGIN {1 = 3}

awk: cmd. line:1:          ^ syntax error



% awk 'BEGIN {_1 = 3}'  # runs fine

---

As an aside, you should use readable variable names in your program to have better maintainability unless you're golfing intentionally.

share|improve this answer

answered 2 hours ago

heemaylheemayl

36.2k378108

add a comment | 

awk does not allow digit-only variable names (and variable names can't begin with a digit as well), so _1 is a trick to prepend _ in front of 1; so, _1 is a variable name in your awk program, which happens to be an array in this case.

Here is an example:

% awk 'BEGIN {1 = 3}'

awk: cmd. line:1: BEGIN {1 = 3}

awk: cmd. line:1:          ^ syntax error



% awk 'BEGIN {_1 = 3}'  # runs fine

---

As an aside, you should use readable variable names in your program to have better maintainability unless you're golfing intentionally.

share|improve this answer

answered 2 hours ago

heemaylheemayl

36.2k378108

% awk 'BEGIN {1 = 3}'

awk: cmd. line:1: BEGIN {1 = 3}

awk: cmd. line:1:          ^ syntax error



% awk 'BEGIN {_1 = 3}'  # runs fine

share|improve this answer

answered 2 hours ago

heemaylheemayl

36.2k378108

answered 2 hours ago

heemaylheemayl

36.2k378108

answered 2 hours ago

heemaylheemayl

36.2k378108