File input (#107)

examples/generic_file.c

@@ -29,22 +29,37 @@ struct MyFile MyFile_create(char *ptr, size_t size);
 //===========
 
 #include <kernaux/generic/file.h>
+#include <kernaux/macro.h>
 #include <stddef.h>
 
-static int MyFile_putc(void *file, unsigned char c);
+static int  MyFile_getc  (void *file);
+static int  MyFile_putc  (void *file, unsigned char c);
+static void MyFile_rewind(void *file);
 
 struct MyFile MyFile_create(char *const ptr, const size_t size)
 {
     struct MyFile my_file;
+    my_file.file.getc = MyFile_getc;
     my_file.file.putc = MyFile_putc;
-    my_file.file.puts = NULL; // "puts" has a default implementation
+    my_file.file.gets  = NULL; // "gets"  has a default implementation
+    my_file.file.puts  = NULL; // "puts"  has a default implementation
+    my_file.file.read  = NULL; // "read"  has a default implementation
     my_file.file.write = NULL; // "write" has a default implementation
+    my_file.file.rewind = MyFile_rewind;
     my_file.ptr = ptr;
     my_file.size = size;
     my_file.pos = 0;
     return my_file;
 }
 
+int MyFile_getc(void *const file)
+{
+    const MyFile my_file = file;
+    if (my_file->pos >= my_file->size) return KERNAUX_EOF;
+    const unsigned char c = my_file->ptr[my_file->pos++];
+    return c;
+}
+
 int MyFile_putc(void *const file, const unsigned char c)
 {
     const MyFile my_file = file;
@@ -53,10 +68,18 @@ int MyFile_putc(void *const file, const unsigned char c)
     return c;
 }
 
+void MyFile_rewind(void *const file)
+{
+    const MyFile my_file = file;
+    my_file->pos = 0;
+}
+
 //========
 // main.c
 //========
 
+#include <kernaux/macro.h>
+
 #include <assert.h>
 #include <string.h>
 
@@ -65,31 +88,47 @@ static const char *const hello = "Hello, World!";
 void example_main()
 {
     char buffer[20];
+    char tmp_buffer[20];
+    size_t count;
+
+    char data[6];
+    memset(&data[0], 0xf0, 3);
+    memset(&data[3], 0xff, 3);
+
 
     // Create file
     struct MyFile my_file = MyFile_create(buffer, sizeof(buffer));
 
     // Write "Hello, World!" to the file
-    {
-        const int result = KernAux_File_puts(&my_file.file, hello);
-        assert(result != KERNAUX_EOF);
-    }
+    assert(KernAux_File_puts(&my_file.file, hello) == true);
 
     // Write null character to the file
-    {
-        const int result = KernAux_File_putc(&my_file.file, '\0');
-        assert(result != KERNAUX_EOF);
-    }
-
-    char data[6];
-    memset(data, 0xff, sizeof(data));
+    assert(KernAux_File_putc(&my_file.file, '\0') != KERNAUX_EOF);
 
     // Write random data to the file
-    {
-        const int result = KernAux_File_write(&my_file.file, data, sizeof(data));
-        assert(result != KERNAUX_EOF);
-    }
+    count = sizeof(data);
+    assert(KernAux_File_write(&my_file.file, data, &count) == true);
+    assert(count == sizeof(data));
 
-    assert(strcmp(buffer, hello) == 0);
+    // Seek to the beginning of the file
+    KernAux_File_rewind(&my_file.file);
+
+    // Read a line from the file
+    count = 14;
+    assert(KernAux_File_gets(&my_file.file, tmp_buffer, &count) == true);
+    assert(count == 14);
+
+    // Read random data from the file
+    count = 6;
+    assert(KernAux_File_read(&my_file.file, &tmp_buffer[14], &count) == true);
+    assert(count == 6);
+
+    // Read a single character from the file
+    assert(KernAux_File_getc(&my_file.file) == KERNAUX_EOF);
+
+
+    assert(strcmp(&buffer[0], hello) == 0);
     assert(memcmp(&buffer[14], data, sizeof(data)) == 0);
+    assert(strcmp(&tmp_buffer[0], hello) == 0);
+    assert(memcmp(&tmp_buffer[14], data, sizeof(data)) == 0);
 }

include/kernaux/generic/file.h

@@ -7,23 +7,34 @@ extern "C" {
 
 #include <kernaux/macro.h>
 
+#include <stdbool.h>
 #include <stddef.h>
 
-#define KERNAUX_EOF (-1)
-
-typedef int (*KernAux_File_Putc) (void *file, unsigned char c);
-typedef int (*KernAux_File_Puts) (void *file, const char *s);
-typedef int (*KernAux_File_Write)(void *file, const void *buffer, size_t count);
+typedef int  (*KernAux_File_Getc)  (void *file);
+typedef int  (*KernAux_File_Putc)  (void *file, unsigned char c);
+typedef bool (*KernAux_File_Gets)  (void *file, void *buffer, size_t *count);
+typedef bool (*KernAux_File_Puts)  (void *file, const char *s);
+typedef bool (*KernAux_File_Read)  (void *file, void *buffer, size_t *count);
+typedef bool (*KernAux_File_Write) (void *file, const void *buffer, size_t *count);
+typedef void (*KernAux_File_Rewind)(void *file);
 
 typedef const struct KernAux_File {
-    KernAux_File_Putc  KERNAUX_PROTECTED_FIELD(putc);
-    KernAux_File_Puts  KERNAUX_PROTECTED_FIELD(puts);
-    KernAux_File_Write KERNAUX_PROTECTED_FIELD(write);
+    KernAux_File_Getc   KERNAUX_PROTECTED_FIELD(getc);
+    KernAux_File_Putc   KERNAUX_PROTECTED_FIELD(putc);
+    KernAux_File_Gets   KERNAUX_PROTECTED_FIELD(gets);
+    KernAux_File_Puts   KERNAUX_PROTECTED_FIELD(puts);
+    KernAux_File_Read   KERNAUX_PROTECTED_FIELD(read);
+    KernAux_File_Write  KERNAUX_PROTECTED_FIELD(write);
+    KernAux_File_Rewind KERNAUX_PROTECTED_FIELD(rewind);
 } *KernAux_File;
 
-int KernAux_File_putc (KernAux_File file, int c);
-int KernAux_File_puts (KernAux_File file, const char *s);
-int KernAux_File_write(KernAux_File file, const void *buffer, size_t count);
+int  KernAux_File_getc  (KernAux_File file);
+int  KernAux_File_putc  (KernAux_File file, int c);
+bool KernAux_File_gets  (KernAux_File file, void *buffer, size_t *count);
+bool KernAux_File_puts  (KernAux_File file, const char *s);
+bool KernAux_File_read  (KernAux_File file, void *buffer, size_t *count);
+bool KernAux_File_write (KernAux_File file, const void *buffer, size_t *count);
+void KernAux_File_rewind(KernAux_File file);
 
 #ifdef __cplusplus
 }

include/kernaux/macro.h

@@ -8,6 +8,8 @@ extern "C" {
 #include <stddef.h>
 #include <stdint.h>
 
+#define KERNAUX_EOF (-1)
+
 #define KERNAUX_CONTAINER_OF(ptr, type, member) \
     ((type*)((uintptr_t)(ptr) - offsetof(type, member)))
 

src/cmdline.c

@@ -5,6 +5,7 @@
 #include <kernaux/assert.h>
 #include <kernaux/cmdline.h>
 #include <kernaux/generic/file.h>
+#include <kernaux/macro.h>
 
 #include <stddef.h>
 #include <string.h>

src/generic/file.c

@@ -4,9 +4,19 @@
 
 #include <kernaux/assert.h>
 #include <kernaux/generic/file.h>
+#include <kernaux/macro.h>
 
+#include <stdbool.h>
 #include <stddef.h>
 
+int KernAux_File_getc(const KernAux_File file)
+{
+    KERNAUX_ASSERT(file);
+    KERNAUX_ASSERT(file->getc);
+
+    return file->getc((void*)file);
+}
+
 int KernAux_File_putc(const KernAux_File file, const int c)
 {
     KERNAUX_ASSERT(file);
@@ -15,43 +25,114 @@ int KernAux_File_putc(const KernAux_File file, const int c)
     return file->putc((void*)file, c);
 }
 
-int KernAux_File_puts(const KernAux_File file, const char *const s)
+bool KernAux_File_gets(
+    const KernAux_File file,
+    void *const buffer,
+    size_t *const count
+) {
+    KERNAUX_ASSERT(file);
+    KERNAUX_ASSERT(buffer);
+    KERNAUX_ASSERT(count);
+    // Reserve space for the terminating null character
+    KERNAUX_ASSERT(*count > 0);
+
+    // Common implementation
+    if (*count == 1) {
+        *((char*)buffer) = '\0';
+        return true;
+    }
+
+    // Inherited implementation
+    if (file->gets) return file->gets((void*)file, buffer, count);
+
+    // Default implementation
+    size_t index = 0;
+    for (char *ss = buffer; index < *count; ++ss, ++index) {
+        const int c = KernAux_File_getc(file);
+        if (c == KERNAUX_EOF || c == '\0' || c == '\n') {
+            *ss = '\0';
+            *count = index + 1;
+            return true;
+        }
+        *ss = c;
+    }
+    ((char*)buffer)[index] = '\0';
+    *count = index;
+    return false;
+}
+
+bool KernAux_File_puts(const KernAux_File file, const char *const s)
 {
     KERNAUX_ASSERT(file);
 
     // Common implementation
-    if (!s) return 0;
+    if (!s) return true;
 
     // Inherited implementation
     if (file->puts) return file->puts((void*)file, s);
 
     // Default implementation
-    size_t ccount = 0;
-    for (const char *ss = s; *ss; ++ss, ++ccount) {
-        if (KernAux_File_putc(file, *ss) == KERNAUX_EOF) return KERNAUX_EOF;
+    for (const char *ss = s; *ss; ++ss) {
+        if (KernAux_File_putc(file, *ss) == KERNAUX_EOF) return false;
     }
-    const int icount = ccount;
-    return icount >= 0 ? icount : 0;
+    return true;
 }
 
-int KernAux_File_write(
+bool KernAux_File_read(
     const KernAux_File file,
-    const void *const buffer,
-    const size_t count
+    void *const buffer,
+    size_t *const count
 ) {
     KERNAUX_ASSERT(file);
+    KERNAUX_ASSERT(buffer);
+    KERNAUX_ASSERT(count);
 
     // Common implementation
-    if (count == 0 || !buffer) return 0;
+    if (*count == 0) return true;
+
+    // Inherited implementation
+    if (file->read) return file->read((void*)file, buffer, count);
+
+    // Default implementation
+    size_t index = 0;
+    for (char *ss = buffer; index < *count; ++ss, ++index) {
+        const int c = KernAux_File_getc(file);
+        if (c == KERNAUX_EOF) {
+            *count = index;
+            return false;
+        }
+        *ss = c;
+    }
+    *count = index;
+    return true;
+}
+
+bool KernAux_File_write(
+    const KernAux_File file,
+    const void *const buffer,
+    size_t *const count
+) {
+    KERNAUX_ASSERT(file);
+    KERNAUX_ASSERT(buffer);
+
+    // Common implementation
+    if (*count == 0) return true;
 
     // Inherited implementation
     if (file->write) return file->write((void*)file, buffer, count);
 
     // Default implementation
-    size_t ccount = 0;
-    for (const char *ss = buffer; ccount < count; ++ss, ++ccount) {
-        if (KernAux_File_putc(file, *ss) == KERNAUX_EOF) return KERNAUX_EOF;
+    size_t index = 0;
+    for (const char *ss = buffer; index < *count; ++ss, ++index) {
+        if (KernAux_File_putc(file, *ss) == KERNAUX_EOF) return false;
     }
-    const int icount = ccount;
-    return icount >= 0 ? icount : 0;
+    return true;
+}
+
+void KernAux_File_rewind(const KernAux_File file)
+{
+    KERNAUX_ASSERT(file);
+    KERNAUX_ASSERT(file->rewind);
+
+    file->rewind((void*)file);
 }