strindex search position of a character string in an other string ind = strindex(haystack, needle, [flag]) [ind, which] = strindex(haystack, needle, [flag]) haystack a character string. The string where to search occurrences of needle. needle a character string or character string vector. The string(s) to search in haystack. ind a vector of indexes. which a vector of indexes. flag a string ("r" for regular expression). strindex searches indexes where needle(i) is found in haystack. For each k it exist an i such that part(haystack,ind(k)+(0:length(needle(i))-1)) is the same string than needle(i). If which argument is required it contains these i. When using the third parameter "r", the needle should be a string of regular expression. And then strindex is going to match it with haystack according to the regular express rules. strindex without regular expression argument is based on Knuth-Morris-Pratt algorithm. This algorithm is more powerful than that used in Scilab 4.x. In some special case, result can be different. Example: // Scilab 5.x -->[k,w]=strindex('aab',['a','ab']) w = 1. 1. 2. k = 1. 2. 2. // Scilab 4.x -->[k,w]=strindex('aab',['a','ab']) w = 1. 1. k = 1. 2. The rules of regular expression are similar to Perl language. For a quick start, see http://perldoc.perl.org/perlrequick.html. For a more in-depth tutorial on, see http://perldoc.perl.org/perlretut.html and for the reference page, see http://perldoc.perl.org/perlre.html string strings regexp strsubst