V3/man/man1/cref.1

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NAME		cref  --  make cross reference listing
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SYNOPSIS	cref____ [ -soi____ ] name1 ...
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DESCRIPTION	CREF makes a cross reference listing
of files in assembler format (see AS(I)).  The files
named as arguments in the command
line are searched for symbols (defined as a succession
of alphabetics, numerics, '.', or '_', beginning with
an alphabetic, '.', or '_').
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The output report is in four columns:
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(1)	(2)	(3)	(4)
symbol	file	see	text as it appears in file
		below
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The third column contains the line number in the file
by default; the -s__ option
will cause the most recent name symbol to appear there
instead.
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CREF uses either an ignore______ file or an only____ file.
If the -i__ option is given, it will take the next
file name to be an ignore______ file; if the -o__ option
is given, the next file name will be taken as an only____ file.
Ignore______ and only____
files should be lists of symbols separated by new lines.
If an ignore______ file is given, all the symbols in the file
will be ignored in columns (1) and (3) of the output.
If an only____ file is given, only symbols appearing in the
file will appear in column (1), but column (3)
will still contain the most recent name encountered.
Only one of the options -i__ or
-o__ may be used.
The default setting
is -i__;
all symbols predefined in the assembler are ignored, except
system call names, which are collected.
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FILES		Files t.0, t.1, t.2, t.3 are
created (i.e. DESTROYED) in the working
directory of anyone
using cref____. This nuisance will be repaired soon.
The output is left in file s.out_____ in the working directory.
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/usr/lem/s.tab is the default ignore______ file.
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SEE ALSO	as(I)
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DIAGNOSTICS	"line too long" -- input line >131 characters
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"symbol too long" -- symbol >20 characters
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"too many symbols" -- >10 symbols in line
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"cannot open t.?" -- bug; see LEM
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"cannot fork; examine t.out" -- can't start sort____
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process; intermediate results are on files t.0___,
t.1___,t.2___,t.3___.  These may be sorted independently
and the results concatenated by the user.
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"cannot sort" -- odd response from sort____; examine
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intermediate results, as above.
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"impossible situation" -- system bug
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"cannot open" file -- one of the input names
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cannot be opened for reading.
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BUGS		The destruction of
unsuspecting users' files should soon be fixed.
A limitation that may eventually go away is the
restriction to assembler language format. There
should be options for FORTRAN, English, etc., lexical
analysis.
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File names longer than eight characters cause misalignment in
the output if tabs are set at every eighth column.

It should
write on the standard output, not s.out.