# mystrtonum --- convert string to number
#
# Arnold Robbins, arnold@skeeve.com, Public Domain
# February, 2004
# Revised June, 2014
function mystrtonum(str, ret, n, i, k, c)
{
if (str ~ /^0[0-7]*$/) {
# octal
n = length(str)
ret = 0
for (i = 1; i <= n; i++) {
c = substr(str, i, 1)
# index() returns 0 if c not in string,
# includes c == "0"
k = index("1234567", c)
ret = ret * 8 + k
}
} else if (str ~ /^0[xX][[:xdigit:]]+$/) {
# hexadecimal
str = substr(str, 3) # lop off leading 0x
n = length(str)
ret = 0
for (i = 1; i <= n; i++) {
c = substr(str, i, 1)
c = tolower(c)
# index() returns 0 if c not in string,
# includes c == "0"
k = index("123456789abcdef", c)
ret = ret * 16 + k
}
} else if (str ~ \
/^[-+]?([0-9]+([.][0-9]*([Ee][0-9]+)?)?|([.][0-9]+([Ee][-+]?[0-9]+)?))$/) {
# decimal number, possibly floating point
ret = str + 0
} else
ret = "NOT-A-NUMBER"
return ret
}
# BEGIN { # gawk test harness
# a[1] = "25"
# a[2] = ".31"
# a[3] = "0123"
# a[4] = "0xdeadBEEF"
# a[5] = "123.45"
# a[6] = "1.e3"
# a[7] = "1.32"
# a[8] = "1.32E2"
#
# for (i = 1; i in a; i++)
# print a[i], strtonum(a[i]), mystrtonum(a[i])
# }
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