mbs − work with multibyte strings
@load "mbs"
byte_count =
mbs_length(string)
count = mbs_split(string, array)
new_string = mbs_join(array)
width = mbs_wcswidth(string)
The mbs
extension adds four functions, as follows:
mbs_length(string)
This function takes a string argument and returns the number of bytes it contains. This is useful in multibyte locales where the number of characters does not equal the number of bytes.
mbs_split(string, array)
This function takes a string value, and an array. It clears the array, and then populates it with the numeric byte values in the string (not the individual characters as strings). It returns the number of elements in the array.
mbs_join(array)
This function is the inverse of mbs_split(). It takes an array of byte values and returns an AWK string composed of those values. NOTE: The function does not validate that the sequence of bytes creates valid strings in the current encoding.
mbs_wcswidth(string[, not_utf8])
This function takes a string and computes the display width (number of columns) taken up by the string. It is similar in function to the standard C wcswidth(3) library routine. By default this function assumes that the current locale is one based on UTF-8. If that is not the case, the caller must pass a second argument that is non-zero. (NOTE: The extension expects a numeric argument to be supplied, so a string value will not work.)
The return value from mbs_wcswidth() can differ from that of the built-in length() function when the string contains combining characters and other such unusual entities.
For the mbs_wcswidth() function, determining if the current locale is based on UTF-8 or not is left up to you, the programmer. The locale naming conventions vary widely (and wildly) from system to system, and this extension isn’t going to venture into that dragon-filled territory.
@load
"mbs"
...
printf "The length in bytes of %s is %d\n", $0,
mbs_length($0)
wcswidth(3)
Arnold D. Robbins
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