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C99 defines {{getenv}} as follows \[[ISO/IEC 9899:1999|AA. C References#ISO/IEC 9899-1999]\] defines {{getenv}} as follows:

The getenv function returns a pointer to a string associated with the matched list member. The string pointed to shall not be modified by the program, but may be overwritten by a subsequent call to the getenv function. If the specified name cannot be found, a null pointer is returned.

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This non-compliant code example modifies the string returned by getenv() by replacing all double quote (") characters with underscores.

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char *env = getenv("TEST_ENV");
if (env == NULL) {
  /* Handle Error */
}

strtr(env,'\"', '_');

Compliant Solution (local copy)

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The modified string may be overwritten by a subsequent call to the getenv() function.   Depending on the implementation, modifying the string returned by getenv() may or may not modify the environment.

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