diff options
Diffstat (limited to 'os.c')
| -rw-r--r-- | os.c | 115 |
1 files changed, 86 insertions, 29 deletions
@@ -1,5 +1,5 @@ /* - * Copyright (C) 1984-2024 Mark Nudelman + * Copyright (C) 1984-2025 Mark Nudelman * * You may distribute under the terms of either the GNU General Public * License or the Less License, as specified in the README file. @@ -32,6 +32,9 @@ #if HAVE_ERRNO_H #include <errno.h> #endif +#if MUST_DEFINE_ERRNO +extern int errno; +#endif #if HAVE_VALUES_H #include <values.h> #endif @@ -58,21 +61,35 @@ static lbool any_data = FALSE; * On other systems, setjmp() doesn't affect the signal mask and so * _setjmp() does not exist; we just use setjmp(). */ +#if HAVE_SIGSETJMP +#define SET_JUMP(label) sigsetjmp(label, 1) +#define LONG_JUMP(label, val) siglongjmp(label, val) +#define JUMP_BUF sigjmp_buf +#else #if HAVE__SETJMP && HAVE_SIGSETMASK -#define SET_JUMP _setjmp -#define LONG_JUMP _longjmp +#define SET_JUMP(label) _setjmp(label) +#define LONG_JUMP(label, val) _longjmp(label, val) +#define JUMP_BUF jmp_buf #else -#define SET_JUMP setjmp -#define LONG_JUMP longjmp +#define SET_JUMP(label) setjmp(label) +#define LONG_JUMP(label, val) longjmp(label, val) +#define JUMP_BUF jmp_buf +#endif #endif -public int reading; +static lbool reading; +static lbool opening; public lbool waiting_for_data; public int consecutive_nulls = 0; +public lbool getting_one_screen = FALSE; /* Milliseconds to wait for data before displaying "waiting for data" message. */ static int waiting_for_data_delay = 4000; -static jmp_buf read_label; +/* Max milliseconds expected to "normally" read and display a screen of text. */ +public int screenfill_ms = 3000; + +static JUMP_BUF read_label; +static JUMP_BUF open_label; extern int sigs; extern int ignore_eoi; @@ -81,6 +98,11 @@ extern int follow_mode; extern int scanning_eof; extern char intr_char; extern int is_tty; +extern int quit_if_one_screen; +extern int one_screen; +#if HAVE_TIME +extern time_type less_start_time; +#endif #if !MSDOS_COMPILER extern int tty; #endif @@ -91,6 +113,10 @@ public void init_poll(void) int idelay = (delay == NULL) ? 0 : atoi(delay); if (idelay > 0) waiting_for_data_delay = idelay; + delay = lgetenv("LESS_SCREENFILL_TIME"); + idelay = (delay == NULL) ? 0 : atoi(delay); + if (idelay > 0) + screenfill_ms = idelay; #if USE_POLL #if defined(__APPLE__) /* In old versions of MacOS, poll() does not work with /dev/tty. */ @@ -111,7 +137,11 @@ public void init_poll(void) static int check_poll(int fd, int tty) { struct pollfd poller[2] = { { fd, POLLIN, 0 }, { tty, POLLIN, 0 } }; - int timeout = (waiting_for_data && !(scanning_eof && follow_mode == FOLLOW_NAME)) ? -1 : waiting_for_data_delay; + int timeout = (waiting_for_data && !(scanning_eof && follow_mode == FOLLOW_NAME)) ? -1 : (ignore_eoi && !waiting_for_data) ? 0 : waiting_for_data_delay; +#if HAVE_TIME + if (getting_one_screen && get_time() < less_start_time + screenfill_ms/1000) + return (0); +#endif if (!any_data) { /* @@ -133,6 +163,7 @@ static int check_poll(int fd, int tty) /* Break out of "waiting for data". */ return (READ_INTR); ungetcc_back((char) ch); + return (READ_INTR); } } if (ignore_eoi && exit_F_on_close && (poller[0].revents & (POLLHUP|POLLIN)) == POLLHUP) @@ -161,7 +192,7 @@ public int supports_ctrl_x(void) /* * Like read() system call, but is deliberately interruptible. - * A call to intread() from a signal handler will interrupt + * A call to intio() from a signal handler will interrupt * any pending iread(). */ public ssize_t iread(int fd, unsigned char *buf, size_t len) @@ -188,7 +219,7 @@ start: if (!reading && SET_JUMP(read_label)) { /* - * We jumped here from intread. + * We jumped here from intio. */ reading = FALSE; #if HAVE_SIGPROCMASK @@ -238,7 +269,7 @@ start: } #endif #if USE_POLL - if (is_tty && fd != tty && use_poll) + if (is_tty && fd != tty && use_poll && !(quit_if_one_screen && one_screen)) { int ret = check_poll(fd, tty); if (ret != 0) @@ -251,24 +282,22 @@ start: } #else #if MSDOS_COMPILER==WIN32C - if (win32_kbhit()) + if (win32_kbhit2(TRUE)) { int c; c = WIN32getch(); - if (c == intr_char) - { - sigs |= S_INTERRUPT; - reading = FALSE; - return (READ_INTR); - } - WIN32ungetch(c); + sigs |= S_INTERRUPT; + reading = FALSE; + if (c != CONTROL('C') && c != intr_char) + WIN32ungetch((char) c); + return (READ_INTR); } #endif #endif n = read(fd, buf, len); reading = FALSE; -#if 1 +#if 0 /* * This is a kludge to workaround a problem on some systems * where terminating a remote tty connection causes read() to @@ -292,9 +321,6 @@ start: /* * Certain values of errno indicate we should just retry the read. */ -#if MUST_DEFINE_ERRNO - extern int errno; -#endif #ifdef EINTR if (errno == EINTR) goto start; @@ -314,11 +340,45 @@ start: } /* - * Interrupt a pending iread(). + * Like open() system call, but is interruptible. */ -public void intread(void) +public int iopen(constant char *filename, int flags) { - LONG_JUMP(read_label, 1); + int r; + while (!opening && SET_JUMP(open_label)) + { + opening = FALSE; + if (sigs & S_INTERRUPT) + { + sigs = 0; +#if HAVE_SETTABLE_ERRNO +#ifdef EINTR + errno = EINTR; +#endif +#endif + return -1; + } + psignals(); /* Handle S_STOP or S_WINCH */ + } + opening = TRUE; + r = open(filename, flags); + opening = FALSE; + return r; +} + +/* + * Interrupt a pending iopen() or iread(). + */ +public void intio(void) +{ + if (opening) + { + LONG_JUMP(open_label, 1); + } + if (reading) + { + LONG_JUMP(read_label, 1); + } } /* @@ -363,9 +423,6 @@ public char * errno_message(constant char *filename) char *m; size_t len; #if HAVE_ERRNO -#if MUST_DEFINE_ERRNO - extern int errno; -#endif p = strerror(errno); #else p = "cannot open"; |