P-Scanf

P-Scanf is a lightweight C library that provides safer and more convenient input handling compared to the standard scanf.

Features

• Validates input type: if a user enters a character when an integer is expected, an error is raised.
• Automatically clears the input buffer when using P-Scanf macros.
• Provides safe string handling without the need to predefine buffer sizes (strings are dynamically allocated).
• Automatically frees memory if a memory allocation failure occurs.

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Installation

Using cl.exe (Visual Studio Compiler)

1. Copy the static library libpscanf.lib to:

   C:\Program Files\Microsoft Visual Studio 12.0\VC\lib
   

   To avoid the linker warning:

   warning LNK4099: PDB 'libpscanf.pdb' was not found with 'libpscanf.lib' or at 'libpscanf.pdb'; linking object as if no debug info
   

   Place the libpscanf.pdb file in the same folder as libpscanf.lib.

2. Add the library in Visual Studio:
   Go to Project -> Properties -> Configuration Properties -> Linker -> Input -> Additional Dependencies and add:

   libpscanf.lib
   

3. Copy the header file pscanf.h to:

   C:\Program Files\Microsoft Visual Studio 12.0\VC\include
   

4. Include it in your source code:

   #include <pscanf.h>

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Using Dev-C++

1. Copy the static library libpscanf.a to:

   C:\Program Files\Dev-Cpp\lib
   

2. In Dev-C++, go to Project -> Project Options -> Parameters -> Linker and add:

   -lpscanf
   

3. Copy the header file pscanf.h to:

   C:\Program Files\Dev-Cpp\include
   

Download the library and header file here: PScanf Release v2.0

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Macros

• dataread(_format, _var, ...)
  Reads any type of data from standard input.

• strread(_var, ...)
  Reads a string from standard input. Memory is dynamically allocated.
  Returns 1 if memory allocation fails.

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Functions

• pause()
  Pauses the program and prints:

  Press enter to continue...
  

• sfree()
  Frees all memory allocated by the strread macro.

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Usage Examples

Reading an Integer

#include <stdio.h>
#include <pscanf.h>

int main(void) {
    int a;
    dataread("%d", &a, "Enter an int: ");
    printf("%d\n", a);
    return 0;
}

If the user enters an invalid value (e.g., a character instead of an integer), the error message will be:

Error: Enter an integer value:

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Reading a String

#include <stdio.h>
#include <pscanf.h>

int main(void) {
    string name = { NULL }; 
    strread(&name, "Enter a string: ");
    printf("String: %s - Length: %d\n", name, name.length);
    sfree();
    pause();
    return 0;
}

• name.length gives the string length.

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Iterating Over a String

#include <stdio.h>
#include <pscanf.h>

int main(void) {
    int i;
    string name = { NULL }; 
    strread(&name, "Enter a string: ");
    for (i = 0; i != name.length; ++i)
        printf("%c\n", name.s[i]);
    sfree();
    pause();
    return 0;
}

• name.s gives access to the characters.

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Storing Multiple Strings

#include <stdio.h>
#include <stdint.h>
#include <pscanf.h>
#define MAX_STRINGS (5)

/* Returns 0 if memory was successfully allocated, otherwise 1. */
uint8_t DataEntry(string* name) {
    int i;
    for (i = 0; i != MAX_STRINGS; ++i) {
        /* Braces are required since strread expands into 2 lines of code. */
        strread(&name[i], "Enter string %d: ", i + 1);
    }
    return 0;
}

void PrintData(string* name) {
    int i, j;
    for (i = 0; i != MAX_STRINGS; ++i)
        printf("%s\n", name[i]);
    printf("\n");
    for (i = 0; i != MAX_STRINGS; ++i) {
        for (j = 0; j != name[i].length; ++j)
            printf("%c", name[i].s[j]);
        printf("\n");
    }
}

int main(void) {
    string name[MAX_STRINGS] = { NULL };
    if (DataEntry(name)) return 1;
    PrintData(name);
    sfree();
    pause();
    return 0;
}

Note: Always initialize string variables to NULL.

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Credits

• DevD4v3
  Author and maintainer of P-Scanf.
• Microsoft Corporation
  For providing the cl.exe compiler used to test the library.