Merge pull request #179 from isabekov/master

Update Awk cheat sheet

sheets/awk

@@ -7,6 +7,33 @@ printf '1\n2\n3\n' | awk '{sum += $1} END {print sum}'
 # Using specific character as separator to sum integers from a file or STDIN.
 printf '1:2:3' | awk -F ":" '{print $1+$2+$3}'
 
+# Print line number 12 of file.txt
+awk 'NR==12' file.txt
+
+# Print first field for each record in file.txt
+awk '{print $1}' file.txt
+
+Print only lines that match regex in file.txt
+awk '/regex/' file.txt
+
+# Print only lines that do not match regex in file.txt
+awk '!/regex/' file.txt
+
+# Print any line where field 2 is equal to "foo" in file.txt
+awk '$2 == "foo"' file.txt
+
+# Print lines where field 2 is NOT equal to "foo" in file.txt
+awk '$2 != "foo"' file.txt
+
+# Print line if field 1 matches regex in file.txt
+awk '$1 ~ /regex/' file.txt
+
+# Print line if field 1 does NOT match regex in file.txt
+awk '$1 !~ /regex/' file.txt
+
+# Print lines with more than 80 characters in file.txt
+awk 'length > 80' file.txt
+
 # Print a multiplication table.
 awk -v RS='' '
     {
@@ -100,3 +127,9 @@ awk '
 		}
 	}
 ' FILE
+
+# Remove duplicate lines
+awk '!seen[$0]++' file.txt
+
+# Remove all empty lines
+awk 'NF > 0' file.txt