From 8cb83eee5a58b1fad74c34094ce3afb9e430b5a4 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Mon, 6 May 2024 04:42:50 +0200 Subject: Adding upstream version 2.33.1. Signed-off-by: Daniel Baumann --- Documentation/col.txt | 41 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 41 insertions(+) create mode 100644 Documentation/col.txt (limited to 'Documentation/col.txt') diff --git a/Documentation/col.txt b/Documentation/col.txt new file mode 100644 index 0000000..1098b44 --- /dev/null +++ b/Documentation/col.txt @@ -0,0 +1,41 @@ +# @(#)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. -- cgit v1.2.3