Added tee

2 files changed, 76 insertions, 7 deletions

diff --git a/README.md b/README.md
index 2d090f0..0e0f3b9 100644
--- a/README.md
+++ b/README.md
@@ -2,10 +2,11 @@
 
 Rewrite of some core utilities for educational purposes.
 
-| Name       | Description                               |
-|------------|-------------------------------------------|
-| `mkdir`    | make directories                          |
-| `basename` | strip directory and suffix from filenames |
-| `cut`      | remove sections from each line of files   |
-| `rm`       | remove files or directories               |
-| `seq`      | print a sequence of numbers               |
+| Name       | Description                                                     |
+|------------|-----------------------------------------------------------------|
+| `mkdir`    | make directories                                                |
+| `basename` | strip directory and suffix from filenames                       |
+| `cut`      | remove sections from each line of files                         |
+| `rm`       | remove files or directories                                     |
+| `seq`      | print a sequence of numbers                                     |
+| `tee`      | read from standard input and write to standard output and files |
diff --git a/tee.c b/tee.c
new file mode 100644
index 0000000..4df5074
--- /dev/null
+++ b/tee.c
@@ -0,0 +1,68 @@
+#define _POSIX_C_SOURCE 2 // getopt
+#define _XOPEN_SOURCE 500 // sigaction
+#include <unistd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <errno.h>
+#include <string.h>
+#include <signal.h>
+
+#define BUFFER_SIZE 2048
+
+char	*g_name = "tee";
+
+int		main(int argc, char **argv)
+{
+	int		option;
+	bool	append = false;
+
+	g_name = argv[0];
+
+	struct sigaction action;
+	action.sa_handler = SIG_IGN;
+	action.sa_flags = SA_NODEFER;
+
+	while ((option = getopt(argc, argv, "ai")) != -1)
+	{
+		switch (option)
+		{
+			case 'a':
+				append = true;
+				break;
+			case 'i':
+				sigaction(SIGINT, &action, NULL);
+				break;
+		}
+	}
+
+	size_t	files_num = argc - optind;
+	FILE	**files = calloc(files_num, sizeof(FILE*));
+	if (files == NULL)
+		return EXIT_FAILURE;
+
+	for (size_t i = 0; i < files_num; i++)
+	{
+		files[i] = fopen(argv[optind + i], append ? "a" : "w");
+		if (files[i] == NULL)
+		{
+			fprintf(stderr, "%s: %s: %s\n", g_name, argv[optind + i], strerror(errno));
+			i--;
+			files_num--;
+		}
+	}
+
+	char	buf[BUFFER_SIZE + 1] = {0};
+	size_t	read_size = 0;
+	while ((read_size = fread(buf, 1, BUFFER_SIZE, stdin)) > 0)
+	{
+		fwrite(buf, 1, read_size, stdout);
+		for (size_t i = 0; i < files_num; i++)
+			fwrite(buf, 1, read_size, files[i]);
+	}
+
+	for (size_t i = 0; i < files_num; i++)
+		fclose(files[i]);
+	free(files);
+	return EXIT_SUCCESS;
+}