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Diffstat (limited to 'src/log.c')
| -rw-r--r-- | src/log.c | 995 |
1 files changed, 995 insertions, 0 deletions
diff --git a/src/log.c b/src/log.c new file mode 100644 index 0000000..7de23ee --- /dev/null +++ b/src/log.c @@ -0,0 +1,995 @@ +/* Messages logging. + Copyright (C) 1998-2011, 2015, 2018-2020 Free Software Foundation, + Inc. + +This file is part of GNU Wget. + +GNU Wget is free software; you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation; either version 3 of the License, or +(at your option) any later version. + +GNU Wget is distributed in the hope that it will be useful, +but WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +GNU General Public License for more details. + +You should have received a copy of the GNU General Public License +along with Wget. If not, see <http://www.gnu.org/licenses/>. + +Additional permission under GNU GPL version 3 section 7 + +If you modify this program, or any covered work, by linking or +combining it with the OpenSSL project's OpenSSL library (or a +modified version of that library), containing parts covered by the +terms of the OpenSSL or SSLeay licenses, the Free Software Foundation +grants you additional permission to convey the resulting work. +Corresponding Source for a non-source form of such a combination +shall include the source code for the parts of OpenSSL used as well +as that of the covered work. */ + +#include "wget.h" + +#include <stdio.h> +#include <string.h> +#include <stdlib.h> +#include <stdarg.h> +#include <unistd.h> +#include <assert.h> +#include <errno.h> + +#include "utils.h" +#include "exits.h" +#include "log.h" + +/* 2005-10-25 SMS. + VMS log files are often VFC record format, not stream, so fputs() can + produce multiple records, even when there's no newline terminator in + the buffer. The result is unsightly output with spurious newlines. + Using fprintf() instead of fputs(), along with inhibiting some + fflush() activity below, seems to solve the problem. +*/ +#ifdef __VMS +# define FPUTS( s, f) fprintf( (f), "%s", (s)) +#else /* def __VMS */ +# define FPUTS( s, f) fputs( (s), (f)) +#endif /* def __VMS [else] */ + +/* This file implements support for "logging". Logging means printing + output, plus several additional features: + + - Cataloguing output by importance. You can specify that a log + message is "verbose" or "debug", and it will not be printed unless + in verbose or debug mode, respectively. + + - Redirecting the log to the file. When Wget's output goes to the + terminal, and Wget receives SIGHUP, all further output is + redirected to a log file. When this is the case, Wget can also + print the last several lines of "context" to the log file so that + it does not begin in the middle of a line. For this to work, the + logging code stores the last several lines of context. Callers may + request for certain output not to be stored. + + - Inhibiting output. When Wget receives SIGHUP, but redirecting + the output fails, logging is inhibited. */ + + +/* The file descriptor used for logging. This is NULL before log_init + is called; logging functions log to stderr then. log_init sets it + either to stderr or to a file pointer obtained from fopen(). If + logging is inhibited, logfp is set back to NULL. */ +static FILE *logfp; + +/* Descriptor of the stdout|stderr */ +static FILE *stdlogfp; + +/* Descriptor of the wget.log* file (if created) */ +static FILE *filelogfp; + +/* Name of log file */ +static char *logfile; + +/* Is interactive shell ? */ +static int shell_is_interactive; + +/* A second file descriptor pointing to the temporary log file for the + WARC writer. If WARC writing is disabled, this is NULL. */ +static FILE *warclogfp; + +/* If true, it means logging is inhibited, i.e. nothing is printed or + stored. */ +static bool inhibit_logging; + +/* Whether the last output lines are stored for use as context. */ +static bool save_context_p; + +/* Whether the log is flushed after each command. */ +static bool flush_log_p = true; + +/* Whether any output has been received while flush_log_p was 0. */ +static bool needs_flushing; + +/* In the event of a hang-up, and if its output was on a TTY, Wget + redirects its output to `wget-log'. + + For the convenience of reading this newly-created log, we store the + last several lines ("screenful", hence the choice of 24) of Wget + output, and dump them as context when the time comes. */ +#define SAVED_LOG_LINES 24 + +/* log_lines is a circular buffer that stores SAVED_LOG_LINES lines of + output. log_line_current always points to the position in the + buffer that will be written to next. When log_line_current reaches + SAVED_LOG_LINES, it is reset to zero. + + The problem here is that we'd have to either (re)allocate and free + strings all the time, or limit the lines to an arbitrary number of + characters. Instead of settling for either of these, we do both: + if the line is smaller than a certain "usual" line length (128 + chars by default), a preallocated memory is used. The rare lines + that are longer than 128 characters are malloc'ed and freed + separately. This gives good performance with minimum memory + consumption and fragmentation. */ + +#define STATIC_LENGTH 128 + +static struct log_ln { + char static_line[STATIC_LENGTH + 1]; /* statically allocated + line. */ + char *malloced_line; /* malloc'ed line, for lines of output + larger than 80 characters. */ + char *content; /* this points either to malloced_line + or to the appropriate static_line. + If this is NULL, it means the line + has not yet been used. */ +} log_lines[SAVED_LOG_LINES]; + +/* The current position in the ring. */ +static int log_line_current = -1; + +/* Whether the most recently written line was "trailing", i.e. did not + finish with \n. This is an important piece of information because + the code is always careful to append data to trailing lines, rather + than create new ones. */ +static bool trailing_line; + +static void check_redirect_output (void); + +#define ROT_ADVANCE(num) do { \ + if (++num >= SAVED_LOG_LINES) \ + num = 0; \ +} while (0) + +/* Free the log line index with NUM. This calls free on + ln->malloced_line if it's non-NULL, and it also resets + ln->malloced_line and ln->content to NULL. */ + +static void +free_log_line (int num) +{ + struct log_ln *ln = log_lines + num; + xfree (ln->malloced_line); + ln->content = NULL; +} + +/* Append bytes in the range [start, end) to one line in the log. The + region is not supposed to contain newlines, except for the last + character (at end[-1]). */ + +static void +saved_append_1 (const char *start, const char *end) +{ + int len = end - start; + if (!len) + return; + + /* First, check whether we need to append to an existing line or to + create a new one. */ + if (!trailing_line) + { + /* Create a new line. */ + struct log_ln *ln; + + if (log_line_current == -1) + log_line_current = 0; + else + free_log_line (log_line_current); + ln = log_lines + log_line_current; + if (len > STATIC_LENGTH) + { + ln->malloced_line = strdupdelim (start, end); + ln->content = ln->malloced_line; + } + else + { + memcpy (ln->static_line, start, len); + ln->static_line[len] = '\0'; + ln->content = ln->static_line; + } + } + else + { + /* Append to the last line. If the line is malloc'ed, we just + call realloc and append the new string. If the line is + static, we have to check whether appending the new string + would make it exceed STATIC_LENGTH characters, and if so, + convert it to malloc(). */ + struct log_ln *ln = log_lines + log_line_current; + if (ln->malloced_line) + { + /* Resize malloc'ed line and append. */ + int old_len = strlen (ln->malloced_line); + ln->malloced_line = xrealloc (ln->malloced_line, old_len + len + 1); + memcpy (ln->malloced_line + old_len, start, len); + ln->malloced_line[old_len + len] = '\0'; + /* might have changed due to realloc */ + ln->content = ln->malloced_line; + } + else + { + int old_len = strlen (ln->static_line); + if (old_len + len > STATIC_LENGTH) + { + /* Allocate memory and concatenate the old and the new + contents. */ + ln->malloced_line = xmalloc (old_len + len + 1); + memcpy (ln->malloced_line, ln->static_line, + old_len); + memcpy (ln->malloced_line + old_len, start, len); + ln->malloced_line[old_len + len] = '\0'; + ln->content = ln->malloced_line; + } + else + { + /* Just append to the old, statically allocated + contents. */ + memcpy (ln->static_line + old_len, start, len); + ln->static_line[old_len + len] = '\0'; + ln->content = ln->static_line; + } + } + } + trailing_line = !(end[-1] == '\n'); + if (!trailing_line) + ROT_ADVANCE (log_line_current); +} + +/* Log the contents of S, as explained above. If S consists of + multiple lines, they are logged separately. If S does not end with + a newline, it will form a "trailing" line, to which things will get + appended the next time this function is called. */ + +static void +saved_append (const char *s) +{ + while (*s) + { + const char *end = strchr (s, '\n'); + if (!end) + end = s + strlen (s); + else + ++end; + saved_append_1 (s, end); + s = end; + } +} + +/* Check X against opt.verbose and opt.quiet. The semantics is as + follows: + + * LOG_ALWAYS - print the message unconditionally; + + * LOG_NOTQUIET - print the message if opt.quiet is non-zero; + + * LOG_NONVERBOSE - print the message if opt.verbose is zero; + + * LOG_VERBOSE - print the message if opt.verbose is non-zero. */ +#define CHECK_VERBOSE(x) \ + switch (x) \ + { \ + case LOG_PROGRESS: \ + if (!opt.show_progress) \ + return; \ + break; \ + case LOG_ALWAYS: \ + break; \ + case LOG_NOTQUIET: \ + if (opt.quiet) \ + return; \ + break; \ + case LOG_NONVERBOSE: \ + if (opt.verbose || opt.quiet) \ + return; \ + break; \ + case LOG_VERBOSE: \ + if (!opt.verbose) \ + return; \ + } + +/* Returns the file descriptor for logging. This is LOGFP, except if + called before log_init, in which case it returns stderr. This is + useful in case someone calls a logging function before log_init. + + If logging is inhibited, return NULL. */ + +static FILE * +get_log_fp (void) +{ + if (inhibit_logging) + return NULL; + if (logfp) + return logfp; + return stderr; +} + +static FILE * +get_progress_fp (void) +{ + if (opt.show_progress == true) + return stderr; + return get_log_fp(); +} + +/* Returns the file descriptor for the secondary log file. This is + WARCLOGFP, except if called before log_init, in which case it + returns stderr. This is useful in case someone calls a logging + function before log_init. + + If logging is inhibited, return NULL. */ + +static FILE * +get_warc_log_fp (void) +{ + if (inhibit_logging) + return NULL; + if (warclogfp) + return warclogfp; + if (logfp) + return NULL; + return stderr; +} + +/* Sets the file descriptor for the secondary log file. */ + +void +log_set_warc_log_fp (FILE * fp) +{ + warclogfp = fp; +} + +/* Log a literal string S. The string is logged as-is, without a + newline appended. */ + +void +logputs (enum log_options o, const char *s) +{ + FILE *fp; + FILE *warcfp; + int errno_save = errno; + + check_redirect_output (); + if (o == LOG_PROGRESS) + fp = get_progress_fp (); + else + fp = get_log_fp (); + + errno = errno_save; + + if (fp == NULL) + return; + + warcfp = get_warc_log_fp (); + errno = errno_save; + + CHECK_VERBOSE (o); + + FPUTS (s, fp); + if (warcfp != NULL) + FPUTS (s, warcfp); + if (save_context_p) + saved_append (s); + if (flush_log_p) + logflush (); + else + needs_flushing = true; + + errno = errno_save; +} + +struct logvprintf_state { + char *bigmsg; + int expected_size; + int allocated; +}; + +/* Print a message to the log. A copy of message will be saved to + saved_log, for later reusal by log_dump_context(). + + Normally we'd want this function to loop around vsnprintf until + sufficient room is allocated, as the Linux man page recommends. + However each call to vsnprintf() must be preceded by va_start and + followed by va_end. Since calling va_start/va_end is possible only + in the function that contains the `...' declaration, we cannot call + vsnprintf more than once. Therefore this function saves its state + to logvprintf_state and signals the parent to call it again. + + (An alternative approach would be to use va_copy, but that's not + portable.) */ + +static bool GCC_FORMAT_ATTR (2, 0) +log_vprintf_internal (struct logvprintf_state *state, const char *fmt, + va_list args) +{ + char smallmsg[128]; + char *write_ptr = smallmsg; + int available_size = sizeof (smallmsg); + int numwritten; + FILE *fp = get_log_fp (); + FILE *warcfp = get_warc_log_fp (); + + if (fp == NULL) + return false; + + if (!save_context_p && warcfp == NULL) + { + /* In the simple case just call vfprintf(), to avoid needless + allocation and games with vsnprintf(). */ + vfprintf (fp, fmt, args); + goto flush; + } + + if (state->allocated != 0) + { + write_ptr = state->bigmsg; + available_size = state->allocated; + } + + /* The GNU coding standards advise not to rely on the return value + of sprintf(). However, vsnprintf() is a relatively new function + missing from legacy systems. Therefore I consider it safe to + assume that its return value is meaningful. On the systems where + vsnprintf() is not available, we use the implementation from + snprintf.c which does return the correct value. */ + numwritten = vsnprintf (write_ptr, available_size, fmt, args); + + /* vsnprintf() will not step over the limit given by available_size. + If it fails, it returns either -1 (older implementations) or the + number of characters (not counting the terminating \0) that + *would have* been written if there had been enough room (C99). + In the former case, we double available_size and malloc to get a + larger buffer, and try again. In the latter case, we use the + returned information to build a buffer of the correct size. */ + + if (numwritten == -1) + { + /* Writing failed, and we don't know the needed size. Try + again with doubled size. */ + int newsize = available_size << 1; + state->bigmsg = xrealloc (state->bigmsg, newsize); + state->allocated = newsize; + return false; + } + else if (numwritten >= available_size) + { + /* Writing failed, but we know exactly how much space we + need. */ + int newsize = numwritten + 1; + state->bigmsg = xrealloc (state->bigmsg, newsize); + state->allocated = newsize; + return false; + } + + /* Writing succeeded. */ + if (save_context_p) + saved_append (write_ptr); + FPUTS (write_ptr, fp); + if (warcfp != NULL && warcfp != fp) + FPUTS (write_ptr, warcfp); + xfree (state->bigmsg); + + flush: + if (flush_log_p) + logflush (); + else + needs_flushing = true; + + return true; +} + +/* Flush LOGFP. Useful while flushing is disabled. */ +void +logflush (void) +{ + FILE *fp = get_log_fp (); + FILE *warcfp = get_warc_log_fp (); + if (fp) + { +/* 2005-10-25 SMS. + On VMS, flush only for a terminal. See note at FPUTS macro, above. +*/ +#ifdef __VMS + if (isatty( fileno( fp))) + { + fflush (fp); + } +#else /* def __VMS */ + fflush (fp); +#endif /* def __VMS [else] */ + } + + if (warcfp != NULL) + fflush (warcfp); + + needs_flushing = false; +} + +/* Enable or disable log flushing. */ +void +log_set_flush (bool flush) +{ + if (flush == flush_log_p) + return; + + if (flush == false) + { + /* Disable flushing by setting flush_log_p to 0. */ + flush_log_p = false; + } + else + { + /* Re-enable flushing. If anything was printed in no-flush mode, + flush the log now. */ + if (needs_flushing) + logflush (); + flush_log_p = true; + } +} + +/* (Temporarily) disable storing log to memory. Returns the old + status of storing, with which this function can be called again to + reestablish storing. */ + +bool +log_set_save_context (bool savep) +{ + bool old = save_context_p; + save_context_p = savep; + return old; +} + +/* Print a message to the screen or to the log. The first argument + defines the verbosity of the message, and the rest are as in + printf(3). */ + +void +logprintf (enum log_options o, const char *fmt, ...) +{ + va_list args; + struct logvprintf_state lpstate; + bool done; + int errno_saved = errno; + + check_redirect_output (); + errno = errno_saved; + if (inhibit_logging) + return; + CHECK_VERBOSE (o); + + xzero (lpstate); + errno = 0; + do + { + va_start (args, fmt); + done = log_vprintf_internal (&lpstate, fmt, args); + va_end (args); + + if (done && errno == EPIPE) + exit (WGET_EXIT_GENERIC_ERROR); + } + while (!done); + + errno = errno_saved; +} + +#ifdef ENABLE_DEBUG +/* The same as logprintf(), but does anything only if opt.debug is + true. */ +void +debug_logprintf (const char *fmt, ...) +{ + if (opt.debug) + { + va_list args; + struct logvprintf_state lpstate; + bool done; + +#ifndef TESTING + check_redirect_output (); +#endif + if (inhibit_logging) + return; + + xzero (lpstate); + do + { + va_start (args, fmt); + done = log_vprintf_internal (&lpstate, fmt, args); + va_end (args); + } + while (!done); + } +} +#endif /* ENABLE_DEBUG */ + +/* Open FILE and set up a logging stream. If FILE cannot be opened, + exit with status of 1. */ +void +log_init (const char *file, bool appendp) +{ + if (file) + { + if (HYPHENP (file)) + { + stdlogfp = stdout; + logfp = stdlogfp; + } + else + { + filelogfp = fopen (file, appendp ? "a" : "w"); + if (!filelogfp) + { + fprintf (stderr, "%s: %s: %s\n", exec_name, file, strerror (errno)); + exit (WGET_EXIT_GENERIC_ERROR); + } + logfp = filelogfp; + } + } + else + { + /* The log goes to stderr to avoid collisions with the output if + the user specifies `-O -'. #### Francois Pinard suggests + that it's a better idea to print to stdout by default, and to + stderr only if the user actually specifies `-O -'. He says + this inconsistency is harder to document, but is overall + easier on the user. */ + stdlogfp = stderr; + logfp = stdlogfp; + + if (1 +#ifdef HAVE_ISATTY + && isatty (fileno (logfp)) +#endif + ) + { + /* If the output is a TTY, enable save context, i.e. store + the most recent several messages ("context") and dump + them to a log file in case SIGHUP or SIGUSR1 is received + (or Ctrl+Break is pressed under Windows). */ + save_context_p = true; + } + } + +#ifndef WINDOWS + /* Initialize this values so we don't have to ask every time we print line */ + shell_is_interactive = isatty (STDIN_FILENO); +#endif +} + +/* Close LOGFP (only if we opened it, not if it's stderr), inhibit + further logging and free the memory associated with it. */ +void +log_close (void) +{ + int i; + + if (logfp && logfp != stderr && logfp != stdout) + { + if (logfp == stdlogfp) + stdlogfp = NULL; + if (logfp == filelogfp) + filelogfp = NULL; + fclose (logfp); + } + logfp = NULL; + + inhibit_logging = true; + save_context_p = false; + + for (i = 0; i < SAVED_LOG_LINES; i++) + free_log_line (i); + log_line_current = -1; + trailing_line = false; +} + +/* Dump saved lines to logfp. */ +static void +log_dump_context (void) +{ + int num = log_line_current; + FILE *fp = get_log_fp (); + FILE *warcfp = get_warc_log_fp (); + if (!fp) + return; + + if (num == -1) + return; + if (trailing_line) + ROT_ADVANCE (num); + do + { + struct log_ln *ln = log_lines + num; + if (ln->content) + { + FPUTS (ln->content, fp); + if (warcfp != NULL) + FPUTS (ln->content, warcfp); + } + ROT_ADVANCE (num); + } + while (num != log_line_current); + if (trailing_line) + if (log_lines[log_line_current].content) + { + FPUTS (log_lines[log_line_current].content, fp); + if (warcfp != NULL) + FPUTS (log_lines[log_line_current].content, warcfp); + } + fflush (fp); + fflush (warcfp); +} + +/* String escape functions. */ + +/* Return the number of non-printable characters in SOURCE. + Non-printable characters are determined as per c-ctype.c. */ + +static int +count_nonprint (const char *source) +{ + const char *p; + int cnt; + for (p = source, cnt = 0; *p; p++) + if (!c_isprint (*p)) + ++cnt; + return cnt; +} + +/* Copy SOURCE to DEST, escaping non-printable characters. + + Non-printable refers to anything outside the non-control ASCII + range (32-126) which means that, for example, CR, LF, and TAB are + considered non-printable along with ESC, BS, and other control + chars. This is by design: it makes sure that messages from remote + servers cannot be easily used to deceive the users by mimicking + Wget's output. Disallowing non-ASCII characters is another + necessary security measure, which makes sure that remote servers + cannot garble the screen or guess the local charset and perform + homographic attacks. + + Of course, the above mandates that escnonprint only be used in + contexts expected to be ASCII, such as when printing host names, + URL components, HTTP headers, FTP server messages, and the like. + + ESCAPE is the leading character of the escape sequence. BASE + should be the base of the escape sequence, and must be either 8 for + octal or 16 for hex. + + DEST must point to a location with sufficient room to store an + encoded version of SOURCE. */ + +static void +copy_and_escape (const char *source, char *dest, char escape, int base) +{ + const char *from = source; + char *to = dest; + unsigned char c; + + /* Copy chars from SOURCE to DEST, escaping non-printable ones. */ + switch (base) + { + case 8: + while ((c = *from++) != '\0') + if (c_isprint (c)) + *to++ = c; + else + { + *to++ = escape; + *to++ = '0' + (c >> 6); + *to++ = '0' + ((c >> 3) & 7); + *to++ = '0' + (c & 7); + } + break; + case 16: + while ((c = *from++) != '\0') + if (c_isprint (c)) + *to++ = c; + else + { + *to++ = escape; + *to++ = XNUM_TO_DIGIT (c >> 4); + *to++ = XNUM_TO_DIGIT (c & 0xf); + } + break; + default: + abort (); + } + *to = '\0'; +} + +#define RING_SIZE 3 +struct ringel { + char *buffer; + int size; +}; +static struct ringel ring[RING_SIZE]; /* ring data */ + +static const char * +escnonprint_internal (const char *str, char escape, int base) +{ + static int ringpos; /* current ring position */ + int nprcnt; + + assert (base == 8 || base == 16); + + nprcnt = count_nonprint (str); + if (nprcnt == 0) + /* If there are no non-printable chars in STR, don't bother + copying anything, just return STR. */ + return str; + + { + /* Set up a pointer to the current ring position, so we can write + simply r->X instead of ring[ringpos].X. */ + struct ringel *r = ring + ringpos; + + /* Every non-printable character is replaced with the escape char + and three (or two, depending on BASE) *additional* chars. Size + must also include the length of the original string and one + additional char for the terminating \0. */ + int needed_size = strlen (str) + 1 + (base == 8 ? 3 * nprcnt : 2 * nprcnt); + + /* If the current buffer is uninitialized or too small, + (re)allocate it. */ + if (r->buffer == NULL || r->size < needed_size) + { + r->buffer = xrealloc (r->buffer, needed_size); + r->size = needed_size; + } + + copy_and_escape (str, r->buffer, escape, base); + ringpos = (ringpos + 1) % RING_SIZE; + return r->buffer; + } +} + +/* Return a pointer to a static copy of STR with the non-printable + characters escaped as \ooo. If there are no non-printable + characters in STR, STR is returned. See copy_and_escape for more + information on which characters are considered non-printable. + + DON'T call this function on translated strings because escaping + will break them. Don't call it on literal strings from the source, + which are by definition trusted. If newlines are allowed in the + string, escape and print it line by line because escaping the whole + string will convert newlines to \012. (This is so that expectedly + single-line messages cannot use embedded newlines to mimic Wget's + output and deceive the user.) + + escnonprint doesn't quote its escape character because it is notf + meant as a general and reversible quoting mechanism, but as a quick + way to defang binary junk sent by malicious or buggy servers. + + NOTE: since this function can return a pointer to static data, be + careful to copy its result before calling it again. However, to be + more useful with printf, it maintains an internal ring of static + buffers to return. Currently the ring size is 3, which means you + can print up to three values in the same printf; if more is needed, + bump RING_SIZE. */ + +const char * +escnonprint (const char *str) +{ + return escnonprint_internal (str, '\\', 8); +} + +/* Return a pointer to a static copy of STR with the non-printable + characters escaped as %XX. If there are no non-printable + characters in STR, STR is returned. + + See escnonprint for usage details. */ + +const char * +escnonprint_uri (const char *str) +{ + return escnonprint_internal (str, '%', 16); +} + +#if defined DEBUG_MALLOC || defined TESTING +void +log_cleanup (void) +{ + size_t i; + for (i = 0; i < countof (ring); i++) + xfree (ring[i].buffer); +} +#endif + +/* When SIGHUP or SIGUSR1 are received, the output is redirected + elsewhere. Such redirection is only allowed once. */ +static const char *redirect_request_signal_name; + +/* Redirect output to `wget-log' or back to stdout/stderr. */ + +void +redirect_output (bool to_file, const char *signal_name) +{ + if (to_file && logfp != filelogfp) + { + if (signal_name) + { + fprintf (stderr, "\n%s received.", signal_name); + } + if (!filelogfp) + { + filelogfp = unique_create (DEFAULT_LOGFILE, false, &logfile); + if (filelogfp) + { + fprintf (stderr, _("\nRedirecting output to %s.\n"), + quote (logfile)); + /* Store signal name to tell wget it's permanent redirect to log file */ + redirect_request_signal_name = signal_name; + logfp = filelogfp; + /* Dump the context output to the newly opened log. */ + log_dump_context (); + } + else + { + /* Eek! Opening the alternate log file has failed. Nothing we + can do but disable printing completely. */ + fprintf (stderr, _("%s: %s; disabling logging.\n"), + (logfile) ? logfile : DEFAULT_LOGFILE, strerror (errno)); + inhibit_logging = true; + } + } + else + { + fprintf (stderr, _("\nRedirecting output to %s.\n"), + quote (logfile)); + logfp = filelogfp; + log_dump_context (); + } + } + else if (!to_file && logfp != stdlogfp) + { + logfp = stdlogfp; + log_dump_context (); + } +} + +/* Check whether there's a need to redirect output. */ + +static void +check_redirect_output (void) +{ +#if !defined(WINDOWS) && !defined(__VMS) + /* If it was redirected already to log file by SIGHUP, SIGUSR1 or -o parameter, + * it was permanent. + * If there was no SIGHUP or SIGUSR1 and shell is interactive + * we check if process is fg or bg before every line is printed.*/ + if (!redirect_request_signal_name && shell_is_interactive && !opt.lfilename) + { + pid_t foreground_pgrp = tcgetpgrp (STDIN_FILENO); + + if (foreground_pgrp != -1 && foreground_pgrp != getpgrp () && !opt.quiet) + { + /* Process backgrounded */ + redirect_output (true,NULL); + } + else + { + /* Process foregrounded */ + redirect_output (false,NULL); + } + } +#endif /* !defined(WINDOWS) && !defined(__VMS) */ +} |