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Full Discussion: Best practice for bracket comparisons?
Top Forums Shell Programming and Scripting Best practice for bracket comparisons? Post 302386503 by jim mcnamara on Tuesday 12th of January 2010 03:07:32 PM
Old 01-12-2010
Several points: [[ and [ may not have precisely the same semantics in some shells. example ksh.
try
Code:
type [  
type [[

Comparisons with string values are [ "string" = "string" ], not ==.

anyway - don't hard code values, except perhaps something that will never change,
example: a status return code of zero always means 'ok', so it can never change.

Why do this? because you can put all of the control variables right at the top of the code, so you can change behavior just by editing a few closely located lines of code. The other reason is that you could miss a "1" somewhere during an edit, completely breaking your code.

A lot of code examples on the forums here do not follow that practice because adding extra variables confuses people just starting out in scripting.
 

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LEARN ABOUT OPENDARWIN

err_print_errors

ERR_print_errors(3)						      OpenSSL						       ERR_print_errors(3)

NAME

       ERR_print_errors, ERR_print_errors_fp - print error messages

SYNOPSIS

	#include <openssl/err.h>

	void ERR_print_errors(BIO *bp);
	void ERR_print_errors_fp(FILE *fp);

DESCRIPTION

       ERR_print_errors() is a convenience function that prints the error strings for all errors that OpenSSL has recorded to bp, thus emptying
       the error queue.

       ERR_print_errors_fp() is the same, except that the output goes to a FILE.

       The error strings will have the following format:

	[pid]:error:[error code]:[library name]:[function name]:[reason string]:[file name]:[line]:[optional text message]

       error code is an 8 digit hexadecimal number. library name, function name and reason string are ASCII text, as is optional text message if
       one was set for the respective error code.

       If there is no text string registered for the given error code, the error string will contain the numeric code.

RETURN VALUES

       ERR_print_errors() and ERR_print_errors_fp() return no values.

SEE ALSO

       err(3), ERR_error_string(3), ERR_get_error(3), ERR_load_crypto_strings(3), SSL_load_error_strings(3)

HISTORY

       ERR_print_errors() and ERR_print_errors_fp() are available in all versions of SSLeay and OpenSSL.

0.9.7d								    2002-04-30						       ERR_print_errors(3)
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