github.com/benhoyt/goawk@v1.8.1/testdata/gawk/substr.awk (about)

     1  BEGIN {
     2  	x = "A"
     3  	printf("%-39s\n", substr(x,1,39))
     4  	print substr("abcdef", 0, 2)
     5  	print substr("abcdef", 2.3, 2)
     6  	print substr("abcdef", -1, 2)
     7  	print substr("abcdef", 1, 0)
     8  	print substr("abcdef", 1, -3)
     9  	print substr("abcdef", 1, 2.3)
    10  	print substr("", 1, 2)
    11  	print substr("abcdef", 5, 5)
    12  	print substr("abcdef", 7, 2)
    13  	exit (0)
    14  }