z/OS V1R9.0 UNIX System Services Command ... - Christian Grothoff

Usage Note
Localization
Exit Values
Portability
produces:
63
3. The example
((a=3*4))
echo $a
produces:
12
Related Information
expr, sh, test
let is a built-in shell command.
let uses the following localization environment variables:
v LANG
v LC_ALL
v LC_MESSAGES
v NLSPATH
See Appendix F for more information.
0 The last argument evaluated to a nonzero value
1 The last argument evaluated to a zero value, or the expression contained a
syntax error or tried to divide by zero
POSIX.2. let and ((expression)) are extensions to the POSIX.2 standard. The
POSIX.2 portable facility for arithmetic expression evaluation is $((expression)). See
“Arithmetic Substitution” on page 562 for more information.
The (( )) syntax only works if the set –o korn option is in effect.
lex — Generate a program for lexical tasks
Format
Description
lex [–achlntTv] [–o file.c] [–P proto] [–p prefix] [file.l ...]
lex reads a description of a lexical syntax, in the form of regular expressions and
actions, from file.l. If you do not provide file.l, or if the file is named –, lex reads the
description from standard input (stdin). It produces a set of tables that, together
with additional prototype code from /etc/yylex.c, constitute a lexical analyzer to
scan those expressions. The resulting recognizer is suitable for use with yacc. You
can find detailed information regarding the use of lex in z/OS UNIX System
Services Programming Tools.
let
Chapter 2. Shell command descriptions 343