minimum implementation

wip/peek/Makefile

@@ -0,0 +1 @@
+peek: peek.c

wip/peek/peek.c

@@ -0,0 +1,53 @@
+#include <stdio.h> /* fprintf(3), getc(3), putc(3), EOF */
+#if !defined EX_OK || !defined EX_USAGE
+#	include <sysexits.h>
+#endif
+#include <termios.h> /* tcgetattr(3), tcsetattr(3), struct termios, ECHO */
+#include <unistd.h> /* getopt(3), STDIN_FILENO */
+
+static char *program_name = "peek";
+
+int main(int argc, char *argv[]){
+	int c;
+	int eof;
+	char include_eof;
+	char to_stderr;
+	char to_stdout;
+	struct termios t;
+
+	/* disable terminal echo */
+	tcgetattr(STDIN_FILENO, &t);
+	t.c_lflag &= ~(ECHO);
+	tcsetattr(STDIN_FILENO, TCSAFLUSH, &t);
+
+	eof = EOF;
+	include_eof = 0;
+	to_stderr = 0;
+	to_stdout = 0;
+	while((c = getopt(argc, argv, "1enop:")) != -1)
+		switch(c){
+		case '1': eof = '\n'; break;
+		case 'e': to_stderr = 1; break;
+		case 'n': include_eof = 1; break;
+		case 'o': to_stdout = 1; break;
+		default:
+			fprintf(stderr, "Usage: %s (-1eno) (-p [program])\n",
+				argv[0] == NULL ? program_name : argv[0]);
+			return EX_USAGE;
+		}
+
+	while((c = getc(stdin)) != eof){
+		if(to_stdout && putc(c, stdout) != c)
+			return EX_OK; /* broken pipe */
+		if(to_stderr)
+			putc(c, stderr);
+	}
+
+	if(include_eof && to_stdout)
+		putc(c, stdout);
+
+	if(include_eof && to_stderr)
+		putc(c, stderr);
+
+	return EX_OK;
+}