Awk Help - toupper/tolower

vanand420 · #1 06-08-2012

Hi,

I am learning awk and faced few queries. Kindly suggest on the same. Where it is wrong.

Code:

$ awk '{if (toupper($1) ~ /a/) print $0}' inv 

$ awk '{if (toupper($1) ~ /A/) print $0}' inv -- Why this output
Jan  13  25  15 115
Mar  15  24  34 228
Apr  31  52  63 420
May  16  34  29 208
Aug  15  34  47 316
Jan  21  36  64 620
Mar  24  75  70 495
Apr  21  70  74 514

It should be like this.
Apr  31  52  63 420
Aug  15  34  47 316
Apr  21  70  74 514

$ awk '{if (tolower($1) ~ /A/) print $0}' inv

$ awk '{if (tolower($1) ~ /a/) print $0}' inv  ---why this output
Jan  13  25  15 115
Mar  15  24  34 228
Apr  31  52  63 420
May  16  34  29 208
Aug  15  34  47 316
Jan  21  36  64 620
Mar  24  75  70 495
Apr  21  70  74 514

It should be like this.
Jan  13  25  15 115
Mar  15  24  34 228
May  16  34  29 208
Jan  21  36  64 620
Mar  24  75  70 495

balajesuri · #2 06-08-2012

toupper($1) ~ /A/ => If the first field (converted to uppercase) contains 'A' ""anywhere"" in the string.

Try this instead: toupper($1) ~ /^A/ to filter out the first field ""starting"" with 'A'

And, I'm not able to understand the second requirement. Do you want to search in first field if second character is 'a'?

vanand420 · #3 06-08-2012

Quote:

Originally Posted by balajesuri

toupper($1) ~ /A/ => If the first field (converted to uppercase) contains 'A' ""anywhere"" in the string.

Try this instead: toupper($1) ~ /^A/ to filter out the first field ""starting"" with 'A'

And, I'm not able to understand the second requirement. Do you want to search in first field if the second character is 'a'?

My concern is that in first case, it should pick "A" only not "a" irrespective of the position.

Code:

$ awk '{if (toupper($1) ~ /A/) print $0}' inv -- Why this output
Jan  13  25  15 115
Mar  15  24  34 228
Apr  31  52  63 420
May  16  34  29 208
Aug  15  34  47 316
Jan  21  36  64 620
Mar  24  75  70 495
Apr  21  70  74 514

It should be like this.
Apr  31  52  63 420
Aug  15  34  47 316
Apr  21  70  74 514

balajesuri · #4 06-08-2012

For first case, did you try this? toupper($1) ~ /^A/

For second case,

Code:

# awk 'toupper($1) !~ /^A/ && tolower($1) ~ /a/ {print}' inv
Jan  13  25  15 115
Mar  15  24  34 228
May  16  34  29 208
Jan  21  36  64 620
Mar  24  75  70 495

vbe · #5 06-08-2012

toupper, tolower converts the argument to upper or lowercase...
So what was returned is what is expected...

vanand420 · #6 06-08-2012

Quote:

Originally Posted by vbe

toupper, tolower converts the argument to upper or lowercase...
So what was returned is what is expected...

How it has returned what is expected. Using CYGWIN_NT-5.1

Code:

awk '{if (toupper($1) ~ /A/) print $0}' inv

Scrutinizer · #7 06-08-2012

Then don't use toupper:

Code:

awk '$1~/^A/' inv

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