### 5.2 Searching and Replacing

— Function File: deblank (s)

> Removes the trailing blanks and nulls from the string s. If s is a matrix, deblank trims each row to the length of longest string.

— Function File: findstr (s, t, overlap)

> Return the vector of all positions in the longer of the two strings s and t where an occurrence of the shorter of the two starts. If the optional argument overlap is nonzero, the returned vector can include overlapping positions (this is the default). For example,

>               findstr ("ababab", "a")
>               => [ 1, 3, 5 ]
>               findstr ("abababa", "aba", 0)
>               => [ 1, 5 ]

— Function File: index (s, t)

> Return the position of the first occurrence of the string t in the string s, or 0 if no occurrence is found. For example,

>               index ("Teststring", "t")
>               => 4

> Caution: This function does not work for arrays of strings.

— Function File: rindex (s, t)

> Return the position of the last occurrence of the string t in the string s, or 0 if no occurrence is found. For example,

>               rindex ("Teststring", "t")
>               => 6

> Caution: This function does not work for arrays of strings.

— Function File: split (s, t)

> Divides the string s into pieces separated by t, returning the result in a string array (padded with blanks to form a valid matrix). For example,

>               split ("Test string", "t")
>               => "Tes "
>                       " s  "
>                       "ring"

— Function File: strcmp (s1, s2)

> Compares two character strings, returning true if they are the same, and false otherwise.

> Caution: For compatibility with Matlab, Octave's strcmp function returns true if the character strings are equal, and false otherwise. This is just the opposite of the corresponding C library function.

— Function File: strrep (s, x, y)

> Replaces all occurrences of the substring x of the string s with the string y. For example,

>               strrep ("This is a test string", "is", "&%$")
>               => "Th&%$ &%$ a test string"

— Function File: substr (s, beg, len)

> Return the substring of s which starts at character number beg and is len characters long.

> If OFFSET is negative, extraction starts that far from the end of the string. If LEN is omitted, the substring extends to the end of S.

> For example,

>               substr ("This is a test string", 6, 9)
>               => "is a test"

> > This function is patterned after AWK. You can get the same result by s`(`beg`: (`beg`+` len`- 1))`.