1.4.27 index,rindex,lnblnk: Index or Length of Substring (Sun Studio 12: Fortran Library Reference)

Sun Studio 12: Fortran Library Reference

1.4.27 `index,rindex,lnblnk`: Index or Length of Substring

These functions search through a character string:

`index(``a1``,``a2``)`	Index of first occurrence of string `a2` in string `a1`
`rindex(``a1``,``a2``)`	Index of last occurrence of string `a2` in string `a1`
`lnblnk(``a1``)`	Index of last nonblank in string `a1`

index has the following forms:

1.4.27.1 `index`: First Occurrence of a Substring in a String

The index is an intrinsic function called by:

`n` `= index(` `a1``,` `a2` `)`
`a1`	`character`	Input	Main string
`a2`	`character`	Input	Substring
Return value	`INTEGER`	Output	`n`>0: Index of first occurrence of `a2` in `a1` `n`=0: `a2` does not occur in `a1`.

If declared INTEGER*8, index() will return an INTEGER*8 value when compiled for a 64-bit environment and character variable a1 is a very large character string (greater than 2 Gigabytes).

1.4.27.2 `rindex`: Last Occurrence of a Substring in a String

The function is called by:

*`INTEGER4 rindex` n `= rindex(` `a1``,` `a2` `)`**
`a1`	`character`	Input	Main string
`a2`	`character`	Input	Substring
Return value	*`INTEGER4`** or`INTEGER*8`	Output	`n`>0: Index of last occurrence of `a2` in `a1` `n`=0: `a2` does not occur in `a1`*`INTEGER8`** returned in 64-bit environments

1.4.27.3 `lnblnk`: Last Nonblank in a String

The function is called by:

n = lnblnk( a1 )

a1

character

Input

String

Return value

INTEGER*4 orINTEGER*8

Output

n>0: Index of last nonblank in a1

n=0: a1 is all nonblankINTEGER*8 returned in 64-bit environments

Example: index(), rindex(), lnblnk():

demo% cat tindex.f
*                        123456789012345678901
       character s*24 / ’abcPDQxyz...abcPDQxyz’ /
       INTEGER*4 declen, index, first, last, len, lnblnk, rindex
       declen = len( s )
       first = index( s, ’abc’ )
       last = rindex( s, ’abc’ )
       lastnb = lnblnk( s )
       write(*,*) declen, lastnb
       write(*,*) first, last
       end
demo% f95 tindex.f
demo% a.out
24 21     <- declen is 24  because intrinsic len() returns the declared length of  s
1 13

Note –

Programs compiled to run in a 64-bit environment must declare index, rindex and lnblnk (and their receiving variables) INTEGER*8 to handle very large character strings.