42 lines
1.9 KiB
Plaintext
42 lines
1.9 KiB
Plaintext
# @(#)README 5.1 (Berkeley) 5/22/90
|
|
|
|
col - filter out reverse line feeds.
|
|
|
|
In the 32V source code to col(1) the default behavior was to NOT compress
|
|
spaces into tabs. There was a -h option which caused it to compress spaces
|
|
into tabs. There was no -x flag.
|
|
|
|
The 32V documentation, however, was consistent with the SVID (actually, V7
|
|
at the time) and documented a -x flag (as defined above) while making no
|
|
mention of a -h flag. Just before 4.3BSD went out, CSRG updated the manual
|
|
page to reflect the way the code worked. Suspecting that this was probably
|
|
the wrong way to go, this version adopts the SVID defaults, and no longer
|
|
documents the -h option.
|
|
|
|
The S5 -p flag is not supported because it isn't clear what it does (looks
|
|
like a kludge introduced for a particular printer).
|
|
|
|
Known differences between AT&T's col and this one (# is delimiter):
|
|
Input AT&T col this col
|
|
#\nabc\E7def\n# # def\nabc\r# # def\nabc\n#
|
|
#a# ## #a\n#
|
|
- last line always ends with at least one \n (or \E9)
|
|
#1234567 8\n# #1234567\t8\n# #1234567 8\n#
|
|
- single space not expanded to tab
|
|
-f #a\E8b\n# #ab\n# # b\E9\ra\n#
|
|
- can back up past first line (as far as you want) so you
|
|
*can* have a super script on the first line
|
|
#\E9_\ba\E8\nb\n# #\n_\bb\ba\n# #\n_\ba\bb\n#
|
|
- always print last character written to a position,
|
|
AT&T col claims to do this but doesn't.
|
|
|
|
If a character is to be placed on a line that has been flushed, a warning
|
|
is produced (the AT&T col is silent). The -l flag (not in AT&T col) can
|
|
be used to increase the number of lines buffered to avoid the problem.
|
|
|
|
General algorithm: a limited number of lines are buffered in a linked
|
|
list. When a printable character is read, it is put in the buffer of
|
|
the current line along with the column it's supposed to be in. When
|
|
a line is flushed, the characters in the line are sorted according to
|
|
column and then printed.
|