/* watch -- execute a program repeatedly, displaying output fullscreen * * Based on the original 1991 'watch' by Tony Rems <rembo@unisoft.com> * (with mods and corrections by Francois Pinard). * * Substantially reworked, new features (differences option, SIGWINCH * handling, unlimited command length, long line handling) added Apr 1999 by * Mike Coleman <mkc@acm.org>. * * Changes by Albert Cahalan, 2002-2003. */#define VERSION "0.2.0"#include <ctype.h>#include <getopt.h>#include <signal.h>#include <ncurses.h>#include <stdio.h>#include <stdlib.h>#include <string.h>#include <sys/ioctl.h>#include <time.h>#include <unistd.h>#include <termios.h>#include <locale.h>#include "proc/procps.h"#ifdef FORCE_8BIT#undef isprint#define isprint(x) ( (x>=' '&&x<='~') || (x>=0xa0) )#endifstatic struct option longopts[] = {	{"differences", optional_argument, 0, 'd'},	{"help", no_argument, 0, 'h'},	{"interval", required_argument, 0, 'n'},	{"no-title", no_argument, 0, 't'},	{"version", no_argument, 0, 'v'},	{0, 0, 0, 0}};static char usage[] =    "Usage: %s [-dhntv] [--differences[=cumulative]] [--help] [--interval=<n>] [--no-title] [--version] <command>\n";static char *progname;static int curses_started = 0;static int height = 24, width = 80;static int screen_size_changed = 0;static int first_screen = 1;static int show_title = 2;  // number of lines used, 2 or 0#define min(x,y) ((x) > (y) ? (y) : (x))static void do_usage(void) NORETURN;static void do_usage(void){	fprintf(stderr, usage, progname);	exit(1);}static void do_exit(int status) NORETURN;static void do_exit(int status){	if (curses_started)		endwin();	exit(status);}/* signal handler */static void die(int notused) NORETURN;static void die(int notused){	(void) notused;	do_exit(0);}static voidwinch_handler(int notused){	(void) notused;	screen_size_changed = 1;}static char env_col_buf[24];static char env_row_buf[24];static int incoming_cols;static int incoming_rows;static voidget_terminal_size(void){	struct winsize w;	if(!incoming_cols){  // have we checked COLUMNS?		const char *s = getenv("COLUMNS");		incoming_cols = -1;		if(s && *s){			long t;			char *endptr;			t = strtol(s, &endptr, 0);			if(!*endptr && (t>0) && (t<(long)666)) incoming_cols = (int)t;			width = incoming_cols;			snprintf(env_col_buf, sizeof env_col_buf, "COLUMNS=%d", width);			putenv(env_col_buf);		}	}	if(!incoming_rows){  // have we checked LINES?		const char *s = getenv("LINES");		incoming_rows = -1;		if(s && *s){			long t;			char *endptr;			t = strtol(s, &endptr, 0);			if(!*endptr && (t>0) && (t<(long)666)) incoming_rows = (int)t;			height = incoming_rows;			snprintf(env_row_buf, sizeof env_row_buf, "LINES=%d", height);			putenv(env_row_buf);		}	}	if (incoming_cols<0 || incoming_rows<0){		if (ioctl(2, TIOCGWINSZ, &w) == 0) {			if (incoming_rows<0 && w.ws_row > 0){				height = w.ws_row;				snprintf(env_row_buf, sizeof env_row_buf, "LINES=%d", height);				putenv(env_row_buf);			}			if (incoming_cols<0 && w.ws_col > 0){				width = w.ws_col;				snprintf(env_col_buf, sizeof env_col_buf, "COLUMNS=%d", width);				putenv(env_col_buf);			}		}	}}intmain(int argc, char *argv[]){	int optc;	int option_differences = 0,	    option_differences_cumulative = 0,	    option_help = 0, option_version = 0;	double interval = 2;	char *command;	int command_length = 0;	/* not including final \0 */	setlocale(LC_ALL, "");	progname = argv[0];	while ((optc = getopt_long(argc, argv, "+d::hn:vt", longopts, (int *) 0))	       != EOF) {		switch (optc) {		case 'd':			option_differences = 1;			if (optarg)				option_differences_cumulative = 1;			break;		case 'h':			option_help = 1;			break;		case 't':			show_title = 0;			break;		case 'n':			{				char *str;				interval = strtod(optarg, &str);				if (!*optarg || *str)					do_usage();				if(interval < 0.1)					interval = 0.1;				if(interval > ~0u/1000000)					interval = ~0u/1000000;			}			break;		case 'v':			option_version = 1;			break;		default:			do_usage();			break;		}	}	if (option_version) {		fprintf(stderr, "%s\n", VERSION);		if (!option_help)			exit(0);	}	if (option_help) {		fprintf(stderr, usage, progname);		fputs("  -d, --differences[=cumulative]\thighlight changes between updates\n", stderr);		fputs("\t\t(cumulative means highlighting is cumulative)\n", stderr);		fputs("  -h, --help\t\t\t\tprint a summary of the options\n", stderr);		fputs("  -n, --interval=<seconds>\t\tseconds to wait between updates\n", stderr);		fputs("  -v, --version\t\t\t\tprint the version number\n", stderr);		fputs("  -t, --no-title\t\t\tturns off showing the header\n", stderr);		exit(0);	}	if (optind >= argc)		do_usage();	command = strdup(argv[optind++]);	command_length = strlen(command);	for (; optind < argc; optind++) {		char *endp;		int s = strlen(argv[optind]);		command = realloc(command, command_length + s + 2);	/* space and \0 */		endp = command + command_length;		*endp = ' ';		memcpy(endp + 1, argv[optind], s);		command_length += 1 + s;	/* space then string length */		command[command_length] = '\0';	}	get_terminal_size();	/* Catch keyboard interrupts so we can put tty back in a sane state.  */	signal(SIGINT, die);	signal(SIGTERM, die);	signal(SIGHUP, die);	signal(SIGWINCH, winch_handler);	/* Set up tty for curses use.  */	curses_started = 1;	initscr();	nonl();	noecho();	cbreak();	for (;;) {		time_t t = time(NULL);		char *ts = ctime(&t);		int tsl = strlen(ts);		char *header;		FILE *p;		int x, y;		int oldeolseen = 1;		if (screen_size_changed) {			get_terminal_size();			resizeterm(height, width);			clear();			/* redrawwin(stdscr); */			screen_size_changed = 0;			first_screen = 1;		}		if (show_title) {			// left justify interval and command,			// right justify time, clipping all to fit window width			asprintf(&header, "Every %.1fs: %.*s",				interval, min(width - 1, command_length), command);			mvaddstr(0, 0, header);			if (strlen(header) > (size_t) (width - tsl - 1))				mvaddstr(0, width - tsl - 4, "...  ");			mvaddstr(0, width - tsl + 1, ts);			free(header);		}		if (!(p = popen(command, "r"))) {			perror("popen");			do_exit(2);		}		for (y = show_title; y < height; y++) {			int eolseen = 0, tabpending = 0;			for (x = 0; x < width; x++) {				int c = ' ';				int attr = 0;				if (!eolseen) {					/* if there is a tab pending, just spit spaces until the					   next stop instead of reading characters */					if (!tabpending)						do							c = getc(p);						while (c != EOF && !isprint(c)						       && c != '\n'						       && c != '\t');					if (c == '\n')						if (!oldeolseen && x == 0) {							x = -1;							continue;						} else							eolseen = 1;					else if (c == '\t')						tabpending = 1;					if (c == EOF || c == '\n' || c == '\t')						c = ' ';					if (tabpending && (((x + 1) % 8) == 0))						tabpending = 0;				}				move(y, x);				if (option_differences) {					int oldch = inch();					char oldc = oldch & A_CHARTEXT;					attr = !first_screen					    && (c != oldc						||						(option_differences_cumulative						 && (oldch & A_ATTRIBUTES)));				}				if (attr)					standout();				addch(c);				if (attr)					standend();			}			oldeolseen = eolseen;		}		pclose(p);		first_screen = 0;		refresh();		usleep(interval * 1000000);	}	endwin();	return 0;}