MISRA C:2012 Rule 22.5

A pointer to a FILE object shall not be dereferenced

Description

Rule Definition

A pointer to a FILE object shall not be dereferenced¹ .

Rationale

The Standard states that the address of a FILE object used to control a stream can be significant. Copying that object might not give the same behavior. This rule ensures that you cannot perform such a copy.

Directly manipulating a FILE object might be incompatible with its use as a stream designator.

Troubleshooting

If you expect a rule violation but do not see it, refer to Diagnose Why Coding Standard Violations Do Not Appear as Expected.

Examples

FILE* Pointer Dereferenced

#include <stdio.h>

void func(void) {
    FILE *pf1;
    FILE *pf2;
    FILE f3;

    pf2 = pf1;        /* Compliant */
    f3 = *pf2;        /* Non-compliant */
    pf2->_flags=0;    /* Non-compliant */
 }

In this example, the rule is violated when the FILE* pointer pf2 is dereferenced.

Check Information

Group: Resources

Category: Mandatory

AGC Category: Mandatory

Version History

Introduced in R2015b