first commit

5 files changed, 86 insertions, 0 deletions

diff --git a/README.md b/README.md
new file mode 100644
index 0000000..b036340
--- /dev/null
+++ b/README.md
@@ -0,0 +1 @@
+# cmem
diff --git a/calloc.c b/calloc.c
new file mode 100644
index 0000000..1f3bf66
--- /dev/null
+++ b/calloc.c
@@ -0,0 +1,23 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+int main()
+{
+  char *mem_allocation;
+
+  // 動的メモリ確保(0で初期化)
+  mem_allocation = calloc(20, sizeof(char));
+  if (mem_allocation == NULL) {
+    fprintf(stderr, "メモリ確保失敗\n");
+    return 1;
+  } else {
+    mem_allocation[0] = 't';
+    mem_allocation[1] = 'e';
+    mem_allocation[2] = 's';
+    mem_allocation[3] = 't';
+  }
+
+  printf("格納した文字列 : %s\n", mem_allocation);
+  free(mem_allocation);
+  // => test
+}
diff --git a/malloc.c b/malloc.c
new file mode 100644
index 0000000..8bb81a1
--- /dev/null
+++ b/malloc.c
@@ -0,0 +1,21 @@
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+
+int main()
+{
+  char *mem_allocation;
+
+  // 動的メモリ確保
+  mem_allocation = malloc(20 * sizeof(char));
+  if (mem_allocation == NULL) {
+    fprintf(stderr, "動的メモリ確保失敗\n");
+    return 1;
+  } else {
+    strlcpy(mem_allocation, "Hi, My sweet hearts", 20);
+  }
+
+  printf("格納した文字列 : %s\n", mem_allocation);
+  // => "Hi, My sweet hearts"
+  free(mem_allocation);
+}
diff --git a/memset.c b/memset.c
new file mode 100644
index 0000000..06db271
--- /dev/null
+++ b/memset.c
@@ -0,0 +1,19 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+int main()
+{
+  int i;
+  char *a = malloc(5 * sizeof(char));
+
+  // 配列の要素を全て0に設定
+  memset(a, 0, 5*sizeof(char));
+
+  for (i = 0; i < 5; ++i) {
+    printf("a[%d] = %d,", i, a[i]);
+  }
+
+  // => a[0] = 0, a[1] = 0, a[2] = 0, a[3] = 0, a[4] = 0,
+  free(a);
+}
diff --git a/realloc.c b/realloc.c
new file mode 100644
index 0000000..e0caf86
--- /dev/null
+++ b/realloc.c
@@ -0,0 +1,22 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+int main()
+{
+  char *mem_allocation;
+
+  // 動的メモリ確保
+  mem_allocation = malloc(20 * sizeof(char));
+  if (mem_allocation == NULL) {
+    fprintf(stderr, "メモリ確保失敗\n");
+    return 1;
+  }
+
+  // 動的メモリ再確保
+  mem_allocation = realloc(mem_allocation, 40 * sizeof(char));
+  if (mem_allocation == NULL) {
+    fprintf(stderr, "メモリ確保失敗\n");
+    return 1;
+  }
+  free(mem_allocation);
+}