| .TH LEX 1 |
| .SH NAME |
| lex \- generator of lexical analysis programs |
| .SH SYNOPSIS |
| .B lex |
| [ |
| .B -tvn9 |
| ] |
| [ |
| .I file ... |
| ] |
| .SH DESCRIPTION |
| .I Lex |
| generates programs to be used in simple lexical analysis of text. |
| The input |
| .I files |
| (standard input default) |
| contain regular expressions |
| to be searched for and actions written in C to be executed when |
| expressions are found. |
| .PP |
| A C source program, |
| .B 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. |
| .PP |
| The options have the following meanings. |
| .TP |
| .B -t |
| Place the result on the standard output instead of in file |
| .BR lex.yy.c . |
| .TP |
| .B -v |
| Print a one-line summary of statistics of the generated analyzer. |
| .TP |
| .B -n |
| Opposite of |
| .BR -v ; |
| .B -n |
| is default. |
| .TP |
| .B -9 |
| Adds code to be able to compile through the native C compilers. |
| .SH EXAMPLES |
| This program converts upper case to lower, |
| removes blanks at the end of lines, |
| and replaces multiple blanks by single blanks. |
| .PP |
| .EX |
| %% |
| [A-Z] putchar(yytext[0]+\'a\'-\'A\'); |
| [ ]+$ |
| [ ]+ putchar(\' \'); |
| .EE |
| .SH FILES |
| .TF /sys/lib/lex/ncform |
| .TP |
| .B lex.yy.c |
| output |
| .TP |
| .B /sys/lib/lex/ncform |
| template |
| .SH "SEE ALSO" |
| .IR yacc (1), |
| .IR sed (1) |
| .br |
| M. E. Lesk and E. Schmidt, |
| `LEX\(emLexical Analyzer Generator', |
| .I |
| Unix Research System Programmer's Manual, |
| Tenth Edition, Volume 2. |
| .SH SOURCE |
| .B \*9/src/cmd/lex |
| .SH BUGS |
| Cannot handle |
| .SM UTF. |
| .PP |
| The asteroid to kill this dinosaur is still in orbit. |
