Rot-13: Difference between revisions
Add Limbo rot13 (Luckily, I had already written/tested this.)
(Add Limbo rot13 (Luckily, I had already written/tested this.)) |
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end function
</lang>
=={{header|Limbo}}==
A fairly straightforward version that uses a lookup table, based on Inferno's cat(1).
<lang Limbo>implement Rot13;
include "sys.m"; sys: Sys;
include "draw.m";
Rot13: module
{
init: fn(ctxt: ref Draw->Context, argv: list of string);
};
stdout: ref Sys->FD;
tab: array of int;
init(nil: ref Draw->Context, args: list of string)
{
sys = load Sys Sys->PATH;
stdout = sys->fildes(1);
inittab();
args = tl args;
if(args == nil)
args = "-" :: nil;
for(; args != nil; args = tl args){
file := hd args;
if(file != "-"){
fd := sys->open(file, Sys->OREAD);
if(fd == nil){
sys->fprint(sys->fildes(2), "rot13: cannot open %s: %r\n", file);
raise "fail:bad open";
}
rot13cat(fd, file);
}else
rot13cat(sys->fildes(0), "<stdin>");
}
}
inittab()
{
tab = array[256] of int;
for(i := 0; i < 256; i++)
tab[i] = i;
for(i = 'a'; i <= 'z'; i++)
tab[i] = (((i - 'a') + 13) % 26) + 'a';
for(i = 'A'; i <= 'Z'; i++)
tab[i] = (((i - 'A') + 13) % 26) + 'A';
}
rot13(s: string): string
{
for(i := 0; i < len s; i++) {
if(s[i] < 256)
s[i] = tab[s[i]];
}
return s;
}
rot13cat(fd: ref Sys->FD, file: string)
{
buf := array[Sys->ATOMICIO] of byte;
while((n := sys->read(fd, buf, len buf)) > 0) {
obuf := array of byte (rot13(string buf));
if(sys->write(stdout, obuf, n) < n) {
sys->fprint(sys->fildes(2), "rot13: write error: %r\n");
raise "fail:write error";
}
}
if(n < 0) {
sys->fprint(sys->fildes(2), "rot13: error reading %s: %r\n", file);
raise "fail:read error";
}
}
</lang>
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