Re: 80 characters long

Sounds like this guy has to write stuff to make an IBM mainframe or other hunk of old iron happy (been there, done that).

What you could try (with no guarantees of success ;-) ) is to set local $/ = 80;. This will read the file in chunks of 80 bytes (note that the docs say bytes, but beware that "byte" and "character" are sometimes used interchangeably). You could also try working with sysread, which has an option to read a specific number of bytes.

I'm sure somebody will (or has) come up with a way to do this in a single line with a regex, but my regex mojo is not in that realm.

emc

Information about American English usage here and here.

Any Northeastern US area jobs? I'm currently unemployed.

Comment on Re: 80 characters long

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Re^2: 80 characters long by ikegami (Patriarch) on Sep 27, 2007 at 21:37 UTC
`$/` doesn't help. (And don't forget the RHS needs to be a reference: `local $/ = \80;`) `local $/ = \10; # Easier to visualize than 80. print "$_\n" while <DATA>; __DATA__ abcdefghijklm ABCDEFGHIJKLM` [download] outputs `abcdefghij klm ABCDEF GHIJKLM` [download] instead of `abcdefghij klm ABCDEFGHIJ KLM` [download] `read` (or unbuffered `sysread`) can do it with some coaxing. `my $wrap_len = 10; my $buf = ''; LOOP: for (;;) { while (length($buf) < $wrap_len+1) { my $rv = read(DATA, $buf, $wrap_len+1-length($buf), length($buf) +); die if not defined $rv; last LOOP if not $rv; } ($buf =~ s/^(.*)\n// \|\| $buf =~ s/^(.{0,$wrap_len})//) and print("$1\n"); } print($buf); __DATA__ abcdefghijklm ABCDEFGHIJKLM` [download] The +1 avoids adding a `\n` before another `\n`.	[reply] [d/l] [select]

Replies are listed 'Best First'.

Re^2: 80 characters long
by ikegami (Patriarch) on Sep 27, 2007 at 21:37 UTC

$/ doesn't help. (And don't forget the RHS needs to be a reference: local $/ = \80;)

local $/ = \10;  # Easier to visualize than 80.
print "$_\n" while <DATA>;
__DATA__
abcdefghijklm
ABCDEFGHIJKLM
[download]

outputs

abcdefghij
klm
ABCDEF
GHIJKLM
[download]

instead of

abcdefghij
klm
ABCDEFGHIJ
KLM
[download]

read (or unbuffered sysread) can do it with some coaxing.

my $wrap_len = 10;

my $buf = '';
LOOP:
for (;;) {
   while (length($buf) < $wrap_len+1) {
      my $rv = read(DATA, $buf, $wrap_len+1-length($buf), length($buf)
+);
      die if not defined $rv;
      last LOOP if not $rv;
   }
   
   ($buf =~ s/^(.*)\n// || $buf =~ s/^(.{0,$wrap_len})//)
      and print("$1\n");
}

print($buf);

__DATA__
abcdefghijklm
ABCDEFGHIJKLM
[download]

The +1 avoids adding a \n before another \n.

[reply]
[d/l]
[select]