Make -stdin the default (Fixes #10), add -no-stdin argument, add --help argument

Author: cbdevnet

README.txt

@@ -30,12 +30,14 @@ Options:
 -linespacing <n>	Pad between lines
 
 Flags:
--stdin			Read text from stdin
+-stdin			Deprecated / No-op
+-no-stdin		Disable text content update via stdin
 -windowed		Do not force window to fullscreen
 -independent-lines	Scale lines independently
 -debugboxes		Draw debug boxes
 -disable-text		Do not draw text
 -disable-doublebuffer	What it says on the tin
+-h | -help | --help	Display usage information
 -v[v[v[v]]]		Increase verbosity
 
 Where <colorspec> is either an X Color name (blue, red,
@@ -45,13 +47,14 @@ and <alignspec> is one of n|ne|e|se|s|sw|w|nw
 
 Options must be given before a text argument starts.
 Command line option parsing can be stopped with --,
-eg.: ./xecho -bc blue -fc yellow -- -stdin is cool!
+eg.: ./xecho -bc blue -fc yellow -- -help shows usage information
 
 Text passed via the command line is scanned once for
 control character encodings (\n and \\), which
 are replaced by their ASCII codepoints.
 
-Control characters are handled as follows
+By default, xecho reads text from stdin and appends it to the window
+content. Control characters on stdin are handled as follows
 	\n		Starts new line
 	\f		Clears display
 	\r		Clears current line
@@ -60,7 +63,7 @@ Control characters are handled as follows
 Usage examples:
 
 	while :; do printf "\f%s" "`date`" \
-		&& sleep 1; done | ./xecho -stdin
+		&& sleep 1; done | ./xecho
 
 	Displays the current date updated by every second.
 	The output of `date` is handled by printf to avoid

arguments.c

@@ -60,12 +60,19 @@ int args_parse(CFG* config, int argc, char** argv){
 		else if(!strcmp(argv[i], "-windowed")){
 			config->windowed = true;
 		}
+		//this parameter is now a noop and deprecated, but still recognized for compatability reasons
 		else if(!strcmp(argv[i], "-stdin")){
 			config->handle_stdin = true;
 		}
+		else if(!strcmp(argv[i], "-no-stdin")){
+			config->handle_stdin = false;
+		}
 		else if(!strcmp(argv[i], "-debugboxes")){
 			config->debug_boxes = true;
 		}
+		else if(!strcmp(argv[i], "-help") || !strcmp(argv[i], "--help") || !strcmp(argv[i], "-h")){
+			config->print_usage = true;
+		}
 		else if(!strcmp(argv[i], "-fc")){
 			if(++i < argc && !(config->text_color)){
 				if(!arg_copy(&(config->text_color), argv[i])){
@@ -246,6 +253,10 @@ bool args_sane(CFG* config){
 		fprintf(stderr, "Font name: %s\n", config->font_name);
 	}
 
+	if(config->print_usage){
+		return false;
+	}
+
 	return true;
 }
 

xecho.1

@@ -1,16 +1,16 @@
-.TH XECHO 1 "September 2015" "v1.0"
+.TH XECHO 1 "August 2016" "v1.1"
 
 .SH NAME
 xecho \- Render text to simple X Windows
 
 .SH SYNOPSIS
-.BI "xecho [-font " fontspec "] [-title " title "] [-bc " colorspec "] [-fc " colorspec "] "
+.BI "xecho [-h | -help | --help] [-font " fontspec "] [-title " title "] [-bc " colorspec "] [-fc " colorspec "] "
 .BI "[-dc " fontspec "] [-size " size "] [-maxsize " size "] [-align " alignspec "] "
-.BI "[-padding " n "] [-linespacing " n "] [-stdin] [-independent-lines] [-debugboxes] "
+.BI "[-padding " n "] [-linespacing " n "] [-no-stdin] [-windowed] [-independent-lines] [-debugboxes] "
 .BI "[-disable-text] [-disable-doublebuffer] [-v[v[v[v]]]] " text
 
 .SH DESCRIPTION
-.BR xecho " takes text from the command line or optionally (with " -stdin ") from the standard"
+.BR xecho " takes text from the command line or from the standard"
 input and displays it at the largest possible font size in an X11 window.
 
 .SH OPTIONS
@@ -94,25 +94,22 @@ $ xecho -linespacing 50 "There are 50 pixels\enBetween these lines"
 .SH FLAGS
 
 .TP
-.B -stdin
-Read display text from stdin. This mode allows piping external programs to xecho in order
-to periodically update the displayed text. The following control characters are interpreted
-by this mode
-.RS
-.BR "\en" "	Start new line"
-.RE
-.RS
-.BR "\ef" "	Clear display"
-.RE
-.RS
-.BR "\er" "	Clear current line"
-.RE
-.RS
-.BR "\eb" "	Backspace"
-.RE
+.B -h | -help | --help
+Print usage information.
+
+.TP
+.B -stdin 
+Deprecated / No-op. Reading date from stdin has since become the standard and
+this argument is only provided for compatability reasons.
+
+.TP
+.B -no-stdin
+Disable text content updates from stdin (see
+.B STDIN UPDATE PROTOCOL
+below for more information)
 .RS
 .B Example:
-$ while :; do printf "\ef%s" "$(date)" && sleep 1; done | xecho -stdin
+$ xecho -no-stdin This text can not be updated
 .RE
 
 .TP
@@ -128,28 +125,64 @@ $ xecho -independent-lines "This line will be big\enThis line will be comparativ
 Draw debug boxes to indicate text bounding boxes.
 .RS
 .B Example:
-$ xecho -debugboxes foo 
+$ xecho -debugboxes foo
 .RE
 
 .TP
 .B -disable-text
 Do not print text at all. Might be useful for playing tetris.
 .RS
 .B Example:
-$ xecho -disable-text There goes nothing 
+$ xecho -disable-text There goes nothing
 .RE
 
 .TP
 .B -disable-doublebuffer
 Disable double buffering via the XDBE extension.
+.RS
+.B Example:
+$ xecho -disable-doublebuffer Resizing this window might flicker
+.RE
 
 .TP
 .B -windowed
 Do not try to force full screen display.
+.RS
+.B Example:
+$ xecho -windowed This window can be resized
+.RE
 
 .TP
 .B -v[v[v[v]]]
 Increase log output verbosity.
+.RS
+.B Example:
+$ xecho -vvvv Tell me more!
+.RE
+
+.SH STDIN UPDATE PROTOCOL
+By default, xecho reads text from stdin and appends it to the window content.
+Some control characters are assigned special functions to allow for advanced usage.
+.RS
+.BR "\en" "	Start new line"
+.RE
+.RS
+.BR "\ef" "	Clear display"
+.RE
+.RS
+.BR "\er" "	Clear current line"
+.RE
+.RS
+.BR "\eb" "	Backspace"
+.RE
+.RS
+.B Example:
+$ while :; do printf "\ef%s" "$(date)" && sleep 1; done | xecho
+.RE
+The stdin update facility can be disabled with the
+.B -no-stdin
+argument.
+
 
 .SH BUGS
 Font size calculation might be slow on old systems.

xecho.c

@@ -4,7 +4,7 @@ int usage(char* fn){
 	printf("xecho - Render text to X\n\n");
 	printf("Usage: %s <arguments> <text>\n", fn);
 	printf("Recognized options:\n");
-	printf("\t--\t\t\t\tStop argument parsing,\n\t\t\t\t\ttreat all following arguments as text\n\n");
+	printf("\t--\t\t\t\tStop argument parsing,\n\t\t\t\t\ttreat all following arguments as content text\n\n");
 	printf("\t-font <fontspec>\t\tSelect font by FontConfig name\n\n");
 	printf("\t-fc <colorspec>\t\t\tSet text color by name or HTML code\n\n");
 	printf("\t-bc <colorspec>\t\t\tSet background color by name or code\n\n");
@@ -16,13 +16,17 @@ int usage(char* fn){
 	printf("\t-padding <n>\t\t\tPad text by n pixels\n\n");
 	printf("\t-linespacing <n>\t\tPad lines by n pixels\n\n");
 	printf("Recognized flags:\n");
-	printf("\t-stdin\t\t\t\tUpdate text from stdin,\n\t\t\t\t\t\\f (Form feed) clears text,\n\t\t\t\t\t\\r (Carriage return) clears current line\n\n");
+	printf("\t-no-stdin\t\t\tDisable content updates from stdin\n\n");
 	printf("\t-windowed\t\t\tDo not try to force a fullscreen window\n\n");
 	printf("\t-independent-lines\t\tResize every line individually\n\n");
 	printf("\t-debugboxes\t\t\tDraw debug boxes\n\n");
 	printf("\t-disable-text\t\t\tDo not render text at all.\n\t\t\t\t\tMight be useful for playing tetris.\n\n");
 	printf("\t-disable-doublebuffer\t\tDo not use XDBE\n\n");
+	printf("\t-h | -help | --help\t\tPrint this usage information\n\n");
 	printf("\t-v[v[v]]\t\t\tIncrease output verbosity\n\n");
+	printf("stdin content update protocol:\n");
+	printf("\t\\f (Form feed) clears text,\n");
+	printf("\t\\r (Carriage return) clears current line\n\n");
 	return 1;
 }
 
@@ -43,11 +47,12 @@ int main(int argc, char** argv){
 		.max_size = 0,
 		.alignment = ALIGN_CENTER,
 		.independent_resize = false,
-		.handle_stdin = false,
+		.handle_stdin = true,
 		.debug_boxes = false,
 		.disable_text = false,
 		.double_buffer = true,
 		.windowed = false,
+		.print_usage = false,
 		.force_size = 0,
 		.text_color = NULL,
 		.bg_color = NULL,

xecho.h

@@ -35,6 +35,7 @@ typedef struct /*_CFG_ARGS*/ {
 	bool disable_text;
 	bool double_buffer;
 	bool windowed;
+	bool print_usage;
 	double force_size;
 	char* text_color;
 	char* bg_color;