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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 14:30:35 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 14:30:35 +0000 |
commit | 378c18e5f024ac5a8aef4cb40d7c9aa9633d144c (patch) | |
tree | 44dfb6ca500d32cabd450649b322a42e70a30683 /Documentation/col.txt | |
parent | Initial commit. (diff) | |
download | util-linux-upstream.tar.xz util-linux-upstream.zip |
Adding upstream version 2.38.1.upstream/2.38.1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'Documentation/col.txt')
-rw-r--r-- | Documentation/col.txt | 41 |
1 files changed, 41 insertions, 0 deletions
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. |