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procps/watch.c
Sami Kerola 6dd092412f watch: new usage & fix coding style 
Coding style fixed and more readable help output.

Signed-off-by: Sami Kerola <kerolasa@iki.fi>
2011-12-20 17:17:01 +01:00

705 lines
16 KiB
C
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/*
* 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.
* stderr handling, exec, and beep option added by Morty Abzug, 2008
* Unicode Support added by Jarrod Lowe <procps@rrod.net> in 2009.
*/
#include "config.h"
#include "proc/procps.h"
#include <ctype.h>
#include <errno.h>
#include <errno.h>
#include <getopt.h>
#include <locale.h>
#include <locale.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sys/time.h>
#include <termios.h>
#include <termios.h>
#include <time.h>
#include <unistd.h>
#ifdef WITH_WATCH8BIT
#include <wchar.h>
#include <ncursesw/ncurses.h>
#else
#include <ncurses.h>
#endif /* WITH_WATCH8BIT */
#ifdef FORCE_8BIT
#undef isprint
#define isprint(x) ( (x>=' '&&x<='~') || (x>=0xa0) )
#endif
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 */
static int precise_timekeeping = 0;
#define min(x,y) ((x) > (y) ? (y) : (x))
#define MAX_ANSIBUF 10
static void __attribute__ ((__noreturn__))
usage(FILE * out)
{
fprintf(out,
"\nUsage: %s [options] command\n"
"\nOptions:\n", program_invocation_short_name);
fprintf(out,
" -b, --beep beep if command has a non-zero exit\n"
" -c, --color interpret ANSI color sequences\n"
" -e, --errexit exit if command has a non-zero exit\n"
" -f, --differences highlight changes between updates\n"
" -n, --interval <secs> seconds to wait between updates\n"
" -p, --precise attempt run command in precise intervals\n"
" -t, --no-title turn off header\n"
" -x, --exec pass command to exec instead of \"sh -c\"\n"
" -h, --help display this help text\n"
" -v, --version display version information and exit\n");
fprintf(out, "\nFor more information see watch(1).\n");
exit(out == stderr ? EXIT_FAILURE : EXIT_SUCCESS);
}
static void init_ansi_colors(void)
{
int i;
short ncurses_colors[] = {
COLOR_BLACK, COLOR_RED, COLOR_GREEN, COLOR_YELLOW, COLOR_BLUE,
COLOR_MAGENTA, COLOR_CYAN, COLOR_WHITE
};
for (i = 0; i < 8; i++)
init_pair(i + 1, ncurses_colors[i], -1);
}
static void set_ansi_attribute(const int attrib)
{
switch (attrib) {
case -1:
return;
case 0:
standend();
return;
case 1:
attrset(A_BOLD);
return;
}
if (attrib >= 30 && attrib <= 37) {
color_set(attrib - 29, NULL);
return;
}
}
static void process_ansi(FILE * fp)
{
int i, c, num1, num2;
char buf[MAX_ANSIBUF];
char *nextnum;
c = getc(fp);
if (c != '[') {
ungetc(c, fp);
return;
}
for (i = 0; i < MAX_ANSIBUF; i++) {
c = getc(fp);
/* COLOUR SEQUENCE ENDS in 'm' */
if (c == 'm') {
buf[i] = '\0';
break;
}
if (c < '0' && c > '9' && c != ';') {
while (--i >= 0)
ungetc(buf[i], fp);
return;
}
buf[i] = (char)c;
}
num1 = strtol(buf, &nextnum, 10);
if (nextnum != buf && nextnum[0] != '\0')
num2 = strtol(nextnum + 1, NULL, 10);
else
num2 = -1;
set_ansi_attribute(num1);
set_ansi_attribute(num2);
}
static void __attribute__ ((__noreturn__)) do_exit(int status)
{
if (curses_started)
endwin();
exit(status);
}
/* signal handler */
static void die(int notused __attribute__ ((__unused__)))
{
do_exit(EXIT_SUCCESS);
}
static void winch_handler(int notused __attribute__ ((__unused__)))
{
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 void get_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);
}
}
}
}
/* get current time in usec */
typedef unsigned long long watch_usec_t;
#define USECS_PER_SEC (1000000ull)
watch_usec_t get_time_usec()
{
struct timeval now;
gettimeofday(&now, NULL);
return USECS_PER_SEC * now.tv_sec + now.tv_usec;
}
#ifdef WITH_WATCH8BIT
/* read a wide character from a popen'd stream */
#define MAX_ENC_BYTES 16
wint_t my_getwc(FILE * s);
wint_t my_getwc(FILE * s)
{
/* assuming no encoding ever consumes more than 16 bytes */
char i[MAX_ENC_BYTES];
int byte = 0;
int convert;
int x;
wchar_t rval;
while (1) {
i[byte] = getc(s);
if (i[byte] == EOF) {
return WEOF;
}
byte++;
errno = 0;
mbtowc(NULL, NULL, 0);
convert = mbtowc(&rval, i, byte);
x = errno;
if (convert > 0) {
/* legal conversion */
return rval;
}
if (byte == MAX_ENC_BYTES) {
while (byte > 1) {
/* at least *try* to fix up */
ungetc(i[--byte], s);
}
errno = -EILSEQ;
return WEOF;
}
}
}
#endif /* WITH_WATCH8BIT */
int main(int argc, char *argv[])
{
int optc;
int option_differences = 0,
option_differences_cumulative = 0,
option_exec = 0,
option_beep = 0,
option_color = 0,
option_errexit = 0, option_help = 0, option_version = 0;
double interval = 2;
char *command;
char **command_argv;
int command_length = 0; /* not including final \0 */
watch_usec_t next_loop; /* next loop time in us, used for precise time
* keeping only */
#ifdef WITH_WATCH8BIT
wchar_t *wcommand = NULL;
int wcommand_columns = 0; /* not including final \0 */
int wcommand_characters = 0; /* not including final \0 */
#endif /* WITH_WATCH8BIT */
int pipefd[2];
int status;
pid_t child;
static struct option longopts[] = {
{"color", no_argument, 0, 'c'},
{"differences", optional_argument, 0, 'd'},
{"help", no_argument, 0, 'h'},
{"interval", required_argument, 0, 'n'},
{"beep", no_argument, 0, 'b'},
{"errexit", no_argument, 0, 'e'},
{"exec", no_argument, 0, 'x'},
{"precise", no_argument, 0, 'p'},
{"no-title", no_argument, 0, 't'},
{"version", no_argument, 0, 'v'},
{0, 0, 0, 0}
};
setlocale(LC_ALL, "");
while ((optc =
getopt_long(argc, argv, "+bced::hn:pvtx", longopts, (int *)0))
!= EOF) {
switch (optc) {
case 'b':
option_beep = 1;
break;
case 'c':
option_color = 1;
break;
case 'd':
option_differences = 1;
if (optarg)
option_differences_cumulative = 1;
break;
case 'e':
option_errexit = 1;
break;
case 't':
show_title = 0;
break;
case 'x':
option_exec = 1;
break;
case 'n':
{
char *str;
interval = strtod(optarg, &str);
if (!*optarg || *str)
usage(stderr);
if (interval < 0.1)
interval = 0.1;
if (interval > ~0u / 1000000)
interval = ~0u / 1000000;
}
break;
case 'p':
precise_timekeeping = 1;
break;
case 'h':
usage(stdout);
break;
case 'v':
display_version();
return EXIT_SUCCESS;
default:
usage(stderr);
break;
}
}
if (optind >= argc)
usage(stderr);
/* save for later */
command_argv = &(argv[optind]);
command = strdup(argv[optind++]);
command_length = strlen(command);
for (; optind < argc; optind++) {
char *endp;
int s = strlen(argv[optind]);
/* space and \0 */
command = realloc(command, command_length + s + 2);
endp = command + command_length;
*endp = ' ';
memcpy(endp + 1, argv[optind], s);
/* space then string length */
command_length += 1 + s;
command[command_length] = '\0';
}
#ifdef WITH_WATCH8BIT
/* convert to wide for printing purposes */
/*mbstowcs(NULL, NULL, 0); */
wcommand_characters = mbstowcs(NULL, command, 0);
if (wcommand_characters < 0) {
fprintf(stderr, "Unicode Handling Error\n");
exit(EXIT_FAILURE);
}
wcommand =
(wchar_t *) malloc((wcommand_characters + 1) * sizeof(wcommand));
if (wcommand == NULL) {
fprintf(stderr, "Unicode Handling Error (malloc)\n");
exit(EXIT_FAILURE);
}
mbstowcs(wcommand, command, wcommand_characters + 1);
wcommand_columns = wcswidth(wcommand, -1);
#endif /* WITH_WATCH8BIT */
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();
if (option_color) {
if (has_colors()) {
start_color();
use_default_colors();
init_ansi_colors();
} else
option_color = 0;
}
nonl();
noecho();
cbreak();
if (precise_timekeeping)
next_loop = get_time_usec();
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
*/
int hlen = asprintf(&header, "Every %.1fs: ", interval);
/*
* the rules:
* width < tsl : print nothing
* width < tsl + hlen + 1: print ts
* width = tsl + hlen + 1: print header, ts
* width < tsl + hlen + 4: print header, ..., ts
* width < tsl + hlen + wcommand_columns: print
* header, truncated wcommand,
* ..., ts
* width > "": print header, wcomand, ts
* this is slightly different from how it used to be
*/
if (width >= tsl) {
if (width >= tsl + hlen + 1) {
mvaddstr(0, 0, header);
if (width >= tsl + hlen + 2) {
if (width < tsl + hlen + 4) {
mvaddstr(0,
width - tsl -
4, "... ");
} else {
#ifdef WITH_WATCH8BIT
if (width <
tsl + hlen +
wcommand_columns) {
/* print truncated */
int avail_columns = width - tsl - hlen;
int using_columns = wcommand_columns;
int using_characters = wcommand_characters;
while (using_columns > avail_columns - 4) {
using_characters--;
using_columns
=
wcswidth
(wcommand,
using_characters);
}
mvaddnwstr(0,
hlen,
wcommand,
using_characters);
mvaddstr(0,
width -
tsl -
4,
"... ");
} else {
mvaddwstr(0,
hlen,
wcommand);
}
#else
mvaddnstr(0, hlen,
command,
width - tsl -
hlen);
#endif /* WITH_WATCH8BIT */
}
}
}
mvaddstr(0, width - tsl + 1, ts);
}
free(header);
}
/* allocate pipes */
if (pipe(pipefd) < 0)
err(7, "pipe");
/* flush stdout and stderr, since we're about to do fd stuff */
fflush(stdout);
fflush(stderr);
/* fork to prepare to run command */
child = fork();
if (child < 0) { /* fork error */
err(2, "fork");
} else if (child == 0) { /* in child */
close(pipefd[0]); /* child doesn't need read side of pipe */
close(1); /* prepare to replace stdout with pipe */
if (dup2(pipefd[1], 1) < 0) { /* replace stdout with write side of pipe */
err(3, "dup2");
}
dup2(1, 2); /* stderr should default to stdout */
if (option_exec) { /* pass command to exec instead of system */
if (execvp(command_argv[0], command_argv) == -1) {
err(4, "exec");
}
} else {
status = system(command); /* watch manpage promises sh quoting */
/* propagate command exit status as child exit status */
if (!WIFEXITED(status)) { /* child exits nonzero if command does */
exit(EXIT_FAILURE);
} else {
exit(WEXITSTATUS(status));
}
}
}
/* otherwise, we're in parent */
close(pipefd[1]); /* close write side of pipe */
if ((p = fdopen(pipefd[0], "r")) == NULL)
err(5, "fdopen");
for (y = show_title; y < height; y++) {
int eolseen = 0, tabpending = 0;
#ifdef WITH_WATCH8BIT
wint_t carry = WEOF;
#endif /* WITH_WATCH8BIT */
for (x = 0; x < width; x++) {
#ifdef WITH_WATCH8BIT
wint_t c = ' ';
#else
int c = ' ';
#endif /* WITH_WATCH8BIT */
int attr = 0;
if (!eolseen) {
/* if there is a tab pending, just
* spit spaces until the next stop
* instead of reading characters */
if (!tabpending)
#ifdef WITH_WATCH8BIT
do {
if (carry == WEOF) {
c = my_getwc(p);
} else {
c = carry;
carry = WEOF;
}
} while (c != WEOF
&& !isprint(c)
&& c < 12
&& wcwidth(c) == 0
&& c != L'\n'
&& c != L'\t'
&& (c != L'\033'
|| option_color !=
1));
#else
do
c = getc(p);
while (c != EOF && !isprint(c)
&& c != '\n'
&& c != '\t'
&& (c != L'\033'
|| option_color !=
1));
#endif /* WITH_WATCH8BIT */
if (c == L'\033' && option_color == 1) {
x--;
process_ansi(p);
continue;
}
if (c == L'\n')
if (!oldeolseen && x == 0) {
x = -1;
continue;
} else
eolseen = 1;
else if (c == L'\t')
tabpending = 1;
#ifdef WITH_WATCH8BIT
if (x == width - 1 && wcwidth(c) == 2) {
y++;
x = -1; /* process this double-width */
carry = c; /* character on the next line */
continue; /* because it won't fit here */
}
if (c == WEOF || c == L'\n'
|| c == L'\t')
c = L' ';
#else
if (c == EOF || c == '\n' || c == '\t')
c = ' ';
#endif /* WITH_WATCH8BIT */
if (tabpending && (((x + 1) % 8) == 0))
tabpending = 0;
}
move(y, x);
if (option_differences) {
#ifdef WITH_WATCH8BIT
cchar_t oldc;
in_wch(&oldc);
attr = !first_screen
&& ((wchar_t) c != oldc.chars[0]
||
(option_differences_cumulative
&& (oldc.
attr & A_ATTRIBUTES)));
#else
chtype oldch = inch();
unsigned char oldc = oldch & A_CHARTEXT;
attr = !first_screen
&& ((unsigned char)c != oldc
||
(option_differences_cumulative
&& (oldch & A_ATTRIBUTES)));
#endif /* WITH_WATCH8BIT */
}
if (attr)
standout();
#ifdef WITH_WATCH8BIT
addnwstr((wchar_t *) & c, 1);
#else
addch(c);
#endif /* WITH_WATCH8BIT */
if (attr)
standend();
#ifdef WITH_WATCH8BIT
if (wcwidth(c) == 0) {
x--;
}
if (wcwidth(c) == 2) {
x++;
}
#endif /* WITH_WATCH8BIT */
}
oldeolseen = eolseen;
}
fclose(p);
/* harvest child process and get status, propagated from command */
if (waitpid(child, &status, 0) < 0)
err(8, "waitpid");
/* if child process exited in error, beep if option_beep is set */
if ((!WIFEXITED(status) || WEXITSTATUS(status))) {
if (option_beep)
beep();
if (option_errexit)
exit(8);
}
first_screen = 0;
refresh();
if (precise_timekeeping) {
watch_usec_t cur_time = get_time_usec();
next_loop += USECS_PER_SEC * interval;
if (cur_time < next_loop)
usleep(next_loop - cur_time);
} else
usleep(interval * 1000000);
}
endwin();
return EXIT_SUCCESS;
}
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