Benjamin Hornberger wrote:
> Hi all,
>
> I would like to split a string by whitespace characters, while anything
> between quotes should be recognized as one elements (even if it contains
> whitespace). Let's say I have the string
>
> 'cat dog "ground hog" bird'
>
> I want to split it into ['cat', 'dog', 'ground hog', 'bird'].
Ok, here we go. Found on http://php.net/split and translated to IDL with
some modifications. Any comments are welcome.
;+
; NAME:
; QUOTESPLIT
;
;
; PURPOSE:
; This function splits a scalar string into an array of substrings,
; similar to STRSPLIT(). However, substrings enclosed in single or
; double quotes are not split. Delimiters can be specified.
;
;
; AUTHOR:
; Benjamin Hornberger
; benjamin.hornberger@stonybrook.edu
;
;
; CATEGORY:
; Utilities, string processing
;
;
; CALLING SEQUENCE:
; Result = QUOTESPLIT(String [, Delimiters])
;
;
; RETURN VALUE:
; A string array holding all the substrings of the String
; argument. Each substring is trimmed of leading or trailing blanks
; unless the blanks are within quotes.
;
;
; INPUTS:
; String: String to be split. Must be a scalar string or one
; element string array.
;
;
; OPTIONAL INPUTS:
; Delimiters: A string holding all characters which serve as
; delimiters. Only single characters can be delimiters. The
; String argument will be split on each occurance of one or more
; delimiters except within quotes (single or double). If a
; string array is given, it will be joined by STRJOIN()
; internally. Example: if Delimiters is " ,;", the string will
; be split on each occurance of a space, comma or semicolon, or
; any combination thereof (except within quotes). Default:
; Comma, Semicolon, Space, Tab, Carriage Return and Line Feed.
;
;
; SIDE EFFECTS:
; If the Delimiters argument is passed as string array, it will be
; joined by QUOTESPLIT.
;
;
; EXAMPLES:
; (quotes in the output show space characters)
;
; IDL> petstring = 'cat dog "ground hog" "bird"'
; IDL> pets = QUOTESPLIT(petstring)
; IDL> FOR i = 0, n_elements(pets)-1 DO print, pets[i]
; 'cat'
; 'dog'
; 'ground hog'
; 'bird'
;
; IDL> petstring = " cat , dog ; 'ground hog' : ' bird ' ,"
; IDL> pets = QUOTESPLIT(petstring, " ;,:")
; IDL> FOR i = 0, n_elements(pets)-1 DO print, pets[i]
; 'cat'
; 'dog'
; 'ground hog'
; ' bird '
;
;
; MODIFICATION HISTORY:
; Written: BH 2005-02-04, translated to IDL with some modifications
; from http://php.net/split (User Contributed Note from "moritz").
;-
FUNCTION quotesplit, string, delimiters
on_error, 2
IF n_params() EQ 0 THEN $
message, 'STRING argument required in function QUOTESPLIT'
IF n_elements(string) NE 1 THEN $
message, 'STRING argument must be scalar in function QUOTESPLIT'
count = 0 ;; walk through all characters in string
length = strlen(string)
;; check delimiters
IF n_elements(delimiters) EQ 0 THEN $
delimiters = ',; '+string(9B)+string(10B)+string(13B)
IF n_elements(delimiters) GT 1 THEN delimiters = strjoin(delimiters)
WHILE count LT length DO BEGIN
;; pass over all delimiters
WHILE (count LT length && strpos(delimiters, strmid(string,
count, 1)) NE -1) DO count++
;; double quotes
IF strmid(string, count, 1) EQ '"' THEN BEGIN
count++
start = count
WHILE (count LT length && strmid(string, count, 1) NE '"') DO
count++
IF n_elements(array) EQ 0 THEN $
array = [strmid(string, start, count-start)] ELSE $
array = [array, strmid(string, start, count-start)]
count += 2 ;; jump over 2nd quote
ENDIF ELSE IF strmid(string, count, 1) EQ "'" THEN BEGIN ;;
single quotes
count++
start = count
WHILE (count LT length && strmid(string, count, 1) NE "'") DO
count++
IF n_elements(array) EQ 0 THEN $
array = [strmid(string, start, count-start)] ELSE $
array = [array, strmid(string, start, count-start)]
count += 2 ;; jump over 2nd quote
ENDIF ELSE BEGIN ;; all other characters
start = count
WHILE (count LT length && strpos(delimiters, strmid(string,
count, 1)) EQ -1) DO count++
IF count GT start THEN $
IF n_elements(array) EQ 0 THEN $
array = [strmid(string, start, count-start)] ELSE $
array = [array, strmid(string, start, count-start)]
count++
ENDELSE
ENDWHILE
;; array could still be undefined here if string had only delimiters
;; in it
IF size(array, /type) EQ 0 THEN array = ''
return, array
END
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