Macros attached.
On Wed, 23 Jun 2021 21:26:23 +0100
"Denis M. Wilson" <d...@oxytropis.plus.com> wrote:
> I have macros corresponding to Cs strchr and strrchr functions.
> Do you want me to pass them on?
>
> Denis
>
> On Wed, 23 Jun 2021 21:48:48 +0200
> Wim Stockman <wim.stock...@gmail.com> wrote:
>
> > Is there a function in groff to find the position of a char in a
> > string. So I can split a string into more than one.
> > I found the substring function that can cut based on length. If I
> > could my marker in the string I could cut it there.
> >
> > Kind regards,
> > Wim Stockman
>
>
--
\# .----------------------------.
\# | |
\# | strchr reg string char |
\# | ------ --- ------ ---- |
\# | |
\# | strrchr reg string char |
\# | ------- --- ------ ---- |
\# | |
\# `----------------------------'
.
\# Position of characters in strings
.
\# .strchr reg string char
\# defines the number register to be the first position in
\# string of the character CW char, or \-1 if the character
\# does not occur in the string.
\#Strings are indexed from 0.
.
\# .strrchr reg string char
\# defines the number register to be the last position in
\# string of the character char, or \-1 if the character
\# does not occur in the string.
.
.eo
.de strchr
.nr \$[1] 0-1
.length str-len \$[2]
.nr str-i 0-1 1
.while \n+[str-i]<\n[str-len] \{\
. ds str-tmp \$[2]
. substring str-tmp \n[str-i] \n[str-i]
. if \[str]\*[str-tmp]\[str]\$[3]\[str] \{\
. nr \$[1] \n[str-i]
. break
. \}
.\}
..
.
.de strrchr
.nr \$[1] 0-1
.length str-len \$[2]
.nr str-i \n[str-len] -1
.while \n+[str-i]>=0 \{\
. ds str-tmp \$[2]
. substring str-tmp \n[str-i] \n[str-i]
. if \[str]\*[str-tmp]\[str]\$[3]\[str] \{\
. nr \$[1] \n[str-i]
. break
. \}
.\}
..
.ec
