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Consequently, if the string returned by getenv() needs to be altered, a local copy should be created to ensure that the environment is not directly and unintentionally modified.

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Noncompliant Code Example

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

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For the case where the intent of the non-compliant noncompliant code example is to use the modified value of the environment variable locally and not modify the environment, this compliant solution makes a local copy of that string value, and then modifies the local copy.

const char const *env;
char *copy_of_env;

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

copy_of_env = (char *)malloc(strlen(env) + 1);
if (copy_of_env == NULL) {
  /* Handle Error */
}

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

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For the case where the intent is to modify the environment, this compliant solution will save the altered string back into the environment by using the POSIX setenv() and strdup() functions.

const char const *env;
char *copy_of_env;

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

copy_of_env = strdup(env);
if (copy_of_env == NULL) {
  /* Handle Error */
}

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

if (setenv("TEST_ENV", copy_of_env, 1) != 0) {
  /* Handle Error */
}

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