Learning awk

examples.txt

$ awk '/Jade/ && !/English/' ./students.csv 
5553,Jade,Mathematics,100,,,

$ awk '/Jade/' ./students.csv 
5553,Jade,English,73,,,
5553,Jade,Mathematics,100,,,

$ awk '/Jade/ {print "****"}' ./students.csv 
****
****

$ awk '/Jade/ {print "****"; print $1}' ./students.csv 
****
5553,Jade,English,73,,,
****
5553,Jade,Mathematics,100,,,

$ awk '/Jade/ {print "****"; print $0}' ./students.csv 
****
5553,Jade,English,73,,,
****
5553,Jade,Mathematics,100,,,

$ awk '/Jade/ {print "****"; print $2}' ./students.csv 
****

****


$ awk -F, '/Jade/ {print "****"; print $2}' ./students.csv 
****
Jade
****
Jade

$ awk -F, '/Jade/ {print "****"; print $3}' ./students.csv 
****
English
****
Mathematics

$ awk -F, '/Jade/ {print "****"; print $4}' ./students.csv 
****
73
****
100

$ awk -F, '/Jade/ {print $4}' ./students.csv 
73
100

$ awk -F, '{print $4}' ./students.csv 
Score
96
77
61
97
87
90
81
63
96
73
71
77
65
87
85
70
70
69
89
79
75
62
69
87
86
100
98
84
100
89
91
99
77
62
74
93
77
88

$ awk -F, '/Mathematics/' ./students.csv 
5329,Alix,Mathematics,79,,,
3250,Bronagh,Mathematics,75,,,
5888,Charlie,Mathematics,62,,,
5978,Dean,Mathematics,69,,,
2264,Edmund,Mathematics,87,,,
2307,Fiona,Mathematics,86,,,
1835,Gerry,Mathematics,100,,,
2758,Hettie,Mathematics,98,,,
5787,Iain,Mathematics,84,,,
5553,Jade,Mathematics,100,,,
6139,Kane,Mathematics,89,,,
9301,Lauren,Mathematics,91,,,
9856,Michael,Mathematics,99,,,
6691,Nora,Mathematics,77,,,
4724,Oscar,Mathematics,62,,,
7793,Paula,Mathematics,74,,,
8944,Quentin,Mathematics,93,,,
6112,Rose,Mathematics,77,,,
4145,Steve,Mathematics,88,,,

$ awk -F, '$3 ~ /Mathematics/' ./students.csv 
5329,Alix,Mathematics,79,,,
3250,Bronagh,Mathematics,75,,,
5888,Charlie,Mathematics,62,,,
5978,Dean,Mathematics,69,,,
2264,Edmund,Mathematics,87,,,
2307,Fiona,Mathematics,86,,,
1835,Gerry,Mathematics,100,,,
2758,Hettie,Mathematics,98,,,
5787,Iain,Mathematics,84,,,
5553,Jade,Mathematics,100,,,
6139,Kane,Mathematics,89,,,
9301,Lauren,Mathematics,91,,,
9856,Michael,Mathematics,99,,,
6691,Nora,Mathematics,77,,,
4724,Oscar,Mathematics,62,,,
7793,Paula,Mathematics,74,,,
8944,Quentin,Mathematics,93,,,
6112,Rose,Mathematics,77,,,
4145,Steve,Mathematics,88,,,

$ awk -F, '$3 ~ /Mathematics/ && $4 < 70' ./students.csv 
5888,Charlie,Mathematics,62,,,
5978,Dean,Mathematics,69,,,
4724,Oscar,Mathematics,62,,,

$ awk -F, '$3 ~ /Mathematics/ && $4 < 70 {tally += 1} END {print tally}' ./students.csv 
3

$ awk -F, '$3 ~ /Mathematics/ && $4 < 70 {print $2; tally += 1} END {print tally}' ./students.csv 
Charlie
Dean
Oscar
3

$ awk -F, '$3 ~ /Mathematics/ && $4 < 70 {print $2; tally += 1} END {print "total... %tally"}' ./students.csv 
Charlie
Dean
Oscar
total... %tally

$ awk -F, '$3 ~ /Mathematics/ && $4 < 70 {print $2; tally += 1} END {print "total... $tally"}' ./students.csv 
Charlie
Dean
Oscar
total... $tally

$ awk -F, '$3 ~ /Mathematics/ && $4 < 70 {print $2; tally += 1} END {print total... $tally}' ./students.csv 
awk: syntax error at source line 1
 context is
  $3 ~ /Mathematics/ && $4 < 70 {print $2; tally += 1} END {print >>>  total... <<<  $tally}
awk: illegal statement at source line 1

$ awk -F, '$3 ~ /Mathematics/ && $4 < 70 {print $2; tally += 1} END {print "total..."; print tally}' ./students.csv 
Charlie
Dean
Oscar
total...
3

students.csv