64 lines
2.3 KiB
C
64 lines
2.3 KiB
C
/*
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** 2001 September 22
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**
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** The author disclaims copyright to this source code. In place of
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** a legal notice, here is a blessing:
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**
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** May you do good and not evil.
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** May you find forgiveness for yourself and forgive others.
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** May you share freely, never taking more than you give.
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**
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*************************************************************************
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*/
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#ifndef SWITCH_MPRINTF_H
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#define SWITCH_MPRINTF_H
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SWITCH_BEGIN_EXTERN_C
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/**
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* This routine is a variant of the "sprintf()" from the
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* standard C library. The resulting string is written into memory
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* obtained from malloc() so that there is never a possiblity of buffer
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* overflow. This routine also implement some additional formatting
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* options that are useful for constructing SQL statements.
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*
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* The strings returned by this routine should be freed by calling
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* free().
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*
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* All of the usual printf formatting options apply. In addition, there
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* is a "%q" option. %q works like %s in that it substitutes a null-terminated
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* string from the argument list. But %q also doubles every '\'' character.
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* %q is designed for use inside a string literal. By doubling each '\''
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* character it escapes that character and allows it to be inserted into
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* the string.
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*
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* For example, so some string variable contains text as follows:
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*
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* char *zText = "It's a happy day!";
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*
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* We can use this text in an SQL statement as follows:
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*
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* char *z = switch_mprintf("INSERT INTO TABLES('%q')", zText);
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* switch_core_db_exec(db, z, callback1, 0, 0);
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* free(z);
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*
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* Because the %q format string is used, the '\'' character in zText
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* is escaped and the SQL generated is as follows:
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*
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* INSERT INTO table1 VALUES('It''s a happy day!')
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*
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* This is correct. Had we used %s instead of %q, the generated SQL
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* would have looked like this:
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*
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* INSERT INTO table1 VALUES('It's a happy day!');
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*
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* This second example is an SQL syntax error. As a general rule you
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* should always use %q instead of %s when inserting text into a string
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* literal.
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*/
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SWITCH_DECLARE(char *) switch_mprintf(const char *zFormat, ...);
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SWITCH_DECLARE(char *) switch_vmprintf(const char *zFormat, va_list ap);
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SWITCH_DECLARE(char *) switch_snprintfv(char *zBuf, int n, const char *zFormat, ...);
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SWITCH_END_EXTERN_C
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#endif /* SWITCH_MPRINTF_H */
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