Plan 9 /sys/man/1/lex

NAME

lex – generator of lexical analysis programs

SYNOPSIS

lex [ –tvn9 ] [ file ... ]

DESCRIPTION

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.

EXAMPLES

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(' ');

FILES

lex.yy.c output
/sys/lib/lex/ncform template

SEE ALSO

yacc(1), sed(1)
M. E. Lesk and E. Schmidt, `LEX--Lexical Analyzer Generator', Unix Research System Programmer's Manual, Tenth Edition, Volume 2.

SOURCE

/sys/src/cmd/lex


	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(' ');`


	yacc(1), sed(1) M. E. Lesk and E. Schmidt, `LEX--Lexical Analyzer Generator', Unix Research System Programmer's Manual, Tenth Edition, Volume 2.


	Cannot handle UTF. The asteroid to kill this dinosaur is still in orbit.