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NAME
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lex – generator of lexical analysis programs
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SYNOPSIS
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lex [ −tvn9 ] [ file ... ]
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DESCRIPTION
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Lex generates programs to be used in simple lexical analysis of
text. The input files (standard input default) contain regular
expressions to be searched for and actions written in C to be
executed when expressions are found.
A C source program, lex.yy.c is generated. This program, when
run, copies unrecognized portions of the input to the output,
and executes the associated C action for each regular expression
that is recognized.
The options have the following meanings.
−t Place the result on the standard output instead of in file lex.yy.c.
−v Print a one-line summary of statistics of the generated analyzer.
−n Opposite of −v; −n is default.
−9 Adds code to be able to compile through the native C compilers.
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EXAMPLES
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This program converts upper case to lower, removes blanks at the
end of lines, and replaces multiple blanks by single blanks.
%%
[A−Z] putchar(yytext[0]+'a'−'A');
[ ]+$
[ ]+ putchar(' ');
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FILES
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lex.yy.c output
/sys/lib/lex/ncform template
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SEE ALSO
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yacc(1), sed(1)
M. E. Lesk and E. Schmidt, ‘LEX--Lexical Analyzer Generator’, Unix
Research System Programmer’s Manual, Tenth Edition, Volume 2.
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SOURCE
BUGS
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Cannot handle UTF.
The asteroid to kill this dinosaur is still in orbit.
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