lex(1)lex(1)Namelex - generate lexical analyzer
Syntaxlex [-tvfn] file...
The command generates programs to be used in simple lexical analysis of
text. The input files (standard input default) contain regular expres‐
sions 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. It is compiled using the
following command line:
cc lex.yy.c -ll
This program copies unrecognized portions of the input to the output,
and executes the associated C action for each regular expression that
Options-f Runs a faster compilation (does not pack resulting tables). This
is limited to small programs.
-n Prints no summary information (default option).
-t Writes to standard output instead of to file
-v Prints one-line summary of generated statistics.
In the following example, the command
draws instructions from the file lexcommands, and places the output in
lex.yy.c. The command
[ ]+ putchar(´ ´);
is an example of a program that would be put into a command file. This
program converts upper case to lower, removes blanks at the end of
lines, and replaces multiple blanks by single blanks.
See Alsosed(1), yacc(1)
"LEX - Lexical Analyzer Generator", Supplementary Documents, Volume 2: