- The tabs program clears and sets tab-stops on the terminal. This uses
- the terminfo clear_all_tabs and set_tab capabilities. If either is
- absent, tabs is unable to clear/set tab-stops. The terminal should be
+ The tabs program clears and sets tab-stops on the terminal. This uses
+ the terminfo clear_all_tabs and set_tab capabilities. If either is
+ absent, tabs is unable to clear/set tab-stops. The terminal should be
configured to use hard tabs, e.g.,
stty tab0
- Like clear(1), tabs writes to the standard output. You can redirect
- the standard output to a file (which prevents tabs from actually
- changing the tabstops), and later cat the file to the screen, setting
+ Like clear(1), tabs writes to the standard output. You can redirect
+ the standard output to a file (which prevents tabs from actually
+ changing the tabstops), and later cat the file to the screen, setting
tabstops at that point.
These are hardware tabs, which cannot be queried rapidly by
@@ -77,42 +77,42 @@
tabs -8
- or use the reset program, since the normal initialization sequences do
+ or use the reset program, since the normal initialization sequences do
not ensure that tab-stops are reset.
- -Tname
- Tell tabs which terminal type to use. If this option is not
- given, tabs will use the $TERM environment variable. If that is
- not set, it will use the ansi+tabs entry.
+ -Tname
+ Tell tabs which terminal type to use. If this option is not
+ given, tabs will use the $TERM environment variable. If that is
+ not set, it will use the ansi+tabs entry.
- -d The debugging option shows a ruler line, followed by two data
+ -d The debugging option shows a ruler line, followed by two data
lines. The first data line shows the expected tab-stops marked
with asterisks. The second data line shows the actual tab-stops,
marked with asterisks.
- -n This option tells tabs to check the options and run any debugging
+ -n This option tells tabs to check the options and run any debugging
option, but not to modify the terminal settings.
- -V reports the version of ncurses which was used in this program, and
+ -V reports the version of ncurses which was used in this program, and
exits.
- The tabs program processes a single list of tab stops. The last option
+ The tabs program processes a single list of tab stops. The last option
to be processed which defines a list is the one that determines the
list to be processed.
- Use a single number as an option, e.g., "-5" to set tabs at the given
+ Use a single number as an option, e.g., "-5" to set tabs at the given
interval (in this case 1, 6, 11, 16, 21, etc.). Tabs are repeated up
to the right margin of the screen.
- Use "-0" to clear all tabs.
+ Use "-0" to clear all tabs.
- Use "-8" to set tabs to the standard interval.
+ Use "-8" to set tabs to the standard interval.
X/Open defines several predefined lists of tab stops.
- -a Assembler, IBM S/370, first format
+ -a Assembler, IBM S/370, first format
- -a2 Assembler, IBM S/370, second format
+ -a2 Assembler, IBM S/370, second format
- -c COBOL, normal format
+ -c COBOL, normal format
- -c2 COBOL compact format
+ -c2 COBOL compact format
- -c3 COBOL compact format extended
+ -c3 COBOL compact format extended
- -f FORTRAN
+ -f FORTRAN
- -p PL/I
+ -p PL/I
- -s SNOBOL
+ -s SNOBOL
- -u UNIVAC 1100 Assembler
+ -u UNIVAC 1100 Assembler
- IEEEStd1003.1/TheOpenGroupBaseSpecificationsIssue7
- (POSIX.1-2008) describes a tabs utility. However
+ IEEEStd1003.1/TheOpenGroupBaseSpecificationsIssue7
+ (POSIX.1-2008) describes a tabs utility. However
- o This standard describes a +m option, to set a terminal's left-
+ o This standard describes a +m option, to set a terminal's left-
margin. Very few of the entries in the terminal database provide
- the smgl (set_left_margin) or smglp (set_left_margin_parm)
+ the smgl (set_left_margin) or smglp (set_left_margin_parm)
capability needed to support the feature.
- o There is no counterpart in X/Open Curses Issue 7 for this utility,
- unlike tput(1).
+ o There is no counterpart in X/Open Curses Issue 7 for this utility,
+ unlike tput(1).
- The -d (debug) and -n (no-op) options are extensions not provided by
+ The -d (debug) and -n (no-op) options are extensions not provided by
other implementations.
- A tabs utility appeared in PWB/Unix 1.0 (1977). There was a reduced
- version of the tabs utility in Unix 7th edition and in 3BSD (1979).
+ A tabs utility appeared in PWB/Unix 1.0 (1977). There was a reduced
+ version of the tabs utility in Unix 7th edition and in 3BSD (1979).
The latter supported a single "-n" option (to cause the first tab stop
to be set on the left margin). That option is not documented by POSIX.
- The PWB/Unix tabs utility, which was included in System III (1980),
+ The PWB/Unix tabs utility, which was included in System III (1980),
used built-in tables rather than the terminal database, to support a
half-dozen terminal types. It also had built-in logic to support the
left-margin, as well as a feature for copying the tab settings from a
@@ -182,36 +182,36 @@
Later versions of Unix, e.g., SVr4, added support for the terminal
database, but kept the tables, as a fallback. In an earlier
- development effort, the tab-stop initialization provided by tset (1982)
- and incorporated into tput uses the terminal database,
+ development effort, the tab-stop initialization provided by tset (1982)
+ and incorporated into tput uses the terminal database,
POSIX documents no limits on the number of tab stops. Documentation
for other implementations states that there is a limit on the number of
- tab stops (e.g., 20 in PWB/Unix's tabs utility). While some terminals
+ tab stops (e.g., 20 in PWB/Unix's tabs utility). While some terminals
may not accept an arbitrary number of tab stops, this implementation
will attempt to set tab stops up to the right margin of the screen, if
the given list happens to be that long.
- The Rationale section of the POSIX documentation goes into some detail
- about the ways the committee considered redesigning the tabs and tput
+ The Rationale section of the POSIX documentation goes into some detail
+ about the ways the committee considered redesigning the tabs and tput
utilities, without proposing an improved solution. It comments that
no known historical version of tabs supports the capability of
setting arbitrary tab stops.
- However, the ExplicitLists described in this manual page were
+ However, the ExplicitLists described in this manual page were
implemented in PWB/Unix. Those provide the capability of setting
abitrary tab stops.