From a927c39c0604c24daaddbc67e3c4c6ffdc925e2e Mon Sep 17 00:00:00 2001
From: DTB <trinity@trinity.moe>
Date: Fri, 26 Jul 2024 07:42:05 -0600
Subject: [PATCH] peek(1): update style

---
 src/peek.c | 91 ++++++++++++++++++++++++++++++------------------------
 1 file changed, 50 insertions(+), 41 deletions(-)

diff --git a/src/peek.c b/src/peek.c
index a769e90..cde3ac4 100644
--- a/src/peek.c
+++ b/src/peek.c
@@ -20,60 +20,67 @@
 #include <stdio.h> /* fprintf(3), fgetc(3), perror(3), fputc(3), stderr, stdin,
                     * stdout, EOF, NULL */
 #include <stdlib.h> /* exit(3), EXIT_FAILURE */
-#if !defined EX_IOERR || !defined EX_OK || !defined EX_USAGE
-#	include <sysexits.h>
-#endif
+#include <sysexits.h> /* EX_IOERR, EX_OK, EX_USAGE */
 #include <termios.h> /* tcgetattr(3), tcsetattr(3), struct termios, ECHO */
 #include <unistd.h> /* getopt(3), isatty(3), STDIN_FILENO */
 
-static char *program_name = "peek";
+char *program_name = "peek";
 
 /* Restores terminal echo; otherwise when a user ^Cs the terminal would
  * continue to not display typed text. If sig isn't zero, this will terminate
  * the program. */
-static void restore_echo(int sig){
+static void
+restore_echo(int sig) {
 	static struct termios t;
 
-	tcgetattr(STDIN_FILENO, &t);
-	t.c_lflag |= ECHO;
-	tcsetattr(STDIN_FILENO, TCSAFLUSH, &t);
+	/* Failure isn't reported because this is the termination routine anyway;
+	 * errors will be obvious. */
+	if (tcgetattr(STDIN_FILENO, &t) == 0) {
+		t.c_lflag |= ECHO;
+		(void)tcsetattr(STDIN_FILENO, TCSAFLUSH, &t);
+	}
 
-	/* If, for whatever ungodly reason, exit(3) returns, the user will notice
-	 * their typed characters on the screen. */
-	if(sig != 0)
-		exit(EXIT_FAILURE);
+	if (sig != 0) { exit(EXIT_FAILURE); } /* Terminated by signal. */
 
 	return;
 }
 
-static int ioerr(char *s){ perror(s); restore_echo(0); return EX_IOERR; }
-static int usage(char *s){
-	fprintf(stderr, "Usage: %s (-1enot) (-p [program [arguments...]])\n", s);
+static int
+ioerr(char *argv0) {
+	perror(argv0);
+	restore_echo(0);
+	return EX_IOERR;
+}
+
+static int
+usage(char *argv0) {
+	(void)fprintf(stderr, "Usage: %s [-i]\n", argv0);
 	return EX_USAGE;
 }
 
 int main(int argc, char *argv[]){
-
-	if(argc < 1)
-		return usage(program_name);
-
-	{ /* option parsing */
+	if (argc > 0) { /* option parsing */
 		char allow_nonterminals;
 		int c;
 
+		program_name = argv[0];
+
 		allow_nonterminals = 0;
-		while((c = getopt(argc, argv, "i")) != -1)
-			switch(c){
-			case 'i':	allow_nonterminals = 1; break;
-			default:	return usage(argv[0]);
+		while ((c = getopt(argc, argv, "i")) != -1) {
+			switch (c) {
+				case 'i':	allow_nonterminals = 1; break;
+				default:	return usage(argv[0]);
 			}
+		}
 
-		if(argc > optind)
-			return usage(argv[0]);
+		if (argc > optind) { return usage(argv[0]); }
 
-		if(!allow_nonterminals && isatty(STDIN_FILENO) != 1){
-			fprintf(stderr, "%s: Must be run in a terminal"
-			    " (option -i skips this check)\n", argv[0]);
+		if (!allow_nonterminals && isatty(STDIN_FILENO) != 1) {
+			(void)fprintf(
+			    stderr,
+			    "%s: Must be run in a terminal (option -i skips this check)\n",
+			    argv[0]
+			);
 			return EX_USAGE;
 		}
 	}
@@ -88,28 +95,30 @@ int main(int argc, char *argv[]){
 		struct sigaction act = { 0 };
 
 		act.sa_handler = restore_echo;
-		if(sigaction(SIGINT, &act, NULL) != 0)
-			perror(argv[0]);
+		if(sigaction(SIGINT, &act, NULL) != 0) { perror(program_name); }
 #else
-		if(signal(SIGINT, restore_echo) == SIG_ERR)
-			perror(argv[0]);
+		if(signal(SIGINT, restore_echo) == SIG_ERR) { perror(program_name); }
 #endif
 	}
-	
-	{ /* banish terminal echo */
+
+	/* Banish terminal echo; this terminates when it fails, because this is the
+	 * whole point of the program. */
+	{
 		struct termios t;
 
-		tcgetattr(STDIN_FILENO, &t);
+		if (tcgetattr(STDIN_FILENO, &t) != 0) { return ioerror(program_name); }
 		t.c_lflag ^= ECHO;
-		tcsetattr(STDIN_FILENO, TCSAFLUSH, &t);
+		if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &t) != 0) {
+			return ioerror(program_name);
+		}
 	}
 
-	{ /* actual input loop */
+	{ /* Input loop */
 		int c;
 
-		while((c = fgetc(stdin)) != EOF)
-			if(fputc(c, stdout) == EOF)
-				return ioerr(argv[0]);
+		while ((c = fgetc(stdin)) != EOF) {
+			if(fputc(c, stdout) == EOF) { return ioerr(program_name); }
+		}
 	}
 
 	restore_echo(0);