Merge pull request #3636 from poettering/logs-show-utf8

improve handling of trailing newline in journal logging

3 files changed, 54 insertions, 53 deletions

diff --git a/man/sd_journal_print.xml b/man/sd_journal_print.xml
index 17fdc9c1f2..76542527fc 100644
--- a/man/sd_journal_print.xml
+++ b/man/sd_journal_print.xml
@@ -93,27 +93,21 @@
   <refsect1>
     <title>Description</title>
 
-    <para><function>sd_journal_print()</function> may be used to
-    submit simple, plain text log entries to the system journal. The
-    first argument is a priority value. This is followed by a format
-    string and its parameters, similar to
-    <citerefentry project='man-pages'><refentrytitle>printf</refentrytitle><manvolnum>3</manvolnum></citerefentry>
-    or
+    <para><function>sd_journal_print()</function> may be used to submit simple, plain text log entries to the system
+    journal. The first argument is a priority value. This is followed by a format string and its parameters, similar to
+    <citerefentry project='man-pages'><refentrytitle>printf</refentrytitle><manvolnum>3</manvolnum></citerefentry> or
     <citerefentry project='man-pages'><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
-    The priority value is one of
-    <constant>LOG_EMERG</constant>,
-    <constant>LOG_ALERT</constant>,
-    <constant>LOG_CRIT</constant>,
-    <constant>LOG_ERR</constant>,
-    <constant>LOG_WARNING</constant>,
-    <constant>LOG_NOTICE</constant>,
-    <constant>LOG_INFO</constant>,
-    <constant>LOG_DEBUG</constant>, as defined in
-    <filename>syslog.h</filename>, see
-    <citerefentry project='man-pages'><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>
-    for details. It is recommended to use this call to submit log
-    messages in the application locale or system locale and in UTF-8
-    format, but no such restrictions are enforced.</para>
+    The priority value is one of <constant>LOG_EMERG</constant>, <constant>LOG_ALERT</constant>,
+    <constant>LOG_CRIT</constant>, <constant>LOG_ERR</constant>, <constant>LOG_WARNING</constant>,
+    <constant>LOG_NOTICE</constant>, <constant>LOG_INFO</constant>, <constant>LOG_DEBUG</constant>, as defined in
+    <filename>syslog.h</filename>, see <citerefentry
+    project='man-pages'><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry> for details. It is
+    recommended to use this call to submit log messages in the application locale or system locale and in UTF-8 format,
+    but no such restrictions are enforced. Note that log messages written using this function are generally not
+    expected to end in a new-line character. However, as all trailing whitespace (including spaces, new-lines,
+    tabulators and carriage returns) are automatically stripped from the logged string, it is acceptable to specify one
+    (or more). Empty lines (after trailing whitespace removal) are suppressed. On non-empty lines, leading whitespace
+    (as well as inner whitespace) is left unmodified. </para>
 
     <para><function>sd_journal_printv()</function> is similar to
     <function>sd_journal_print()</function> but takes a variable
@@ -123,35 +117,26 @@
     for more information) instead of the format string. It is
     otherwise equivalent in behavior.</para>
 
-    <para><function>sd_journal_send()</function> may be used to submit
-    structured log entries to the system journal. It takes a series of
-    format strings, each immediately followed by their associated
-    parameters, terminated by <constant>NULL</constant>. The strings
-    passed should be of the format <literal>VARIABLE=value</literal>.
-    The variable name must be in uppercase and consist only of
-    characters, numbers and underscores, and may not begin with an
-    underscore. (All assignments that do not follow this syntax will
-    be ignored.) The value can be of any size and format. It is highly
-    recommended to submit text strings formatted in the UTF-8
-    character encoding only, and submit binary fields only when
-    formatting in UTF-8 strings is not sensible. A number of
-    well-known fields are defined, see
-    <citerefentry><refentrytitle>systemd.journal-fields</refentrytitle><manvolnum>7</manvolnum></citerefentry>
-    for details, but additional application defined fields may be
-    used. A variable may be assigned more than one value per
-    entry.</para>
-
-    <para><function>sd_journal_sendv()</function> is similar to
-    <function>sd_journal_send()</function> but takes an array of
-    <varname>struct iovec</varname> (as defined in
-    <filename>uio.h</filename>, see
-    <citerefentry project='man-pages'><refentrytitle>readv</refentrytitle><manvolnum>3</manvolnum></citerefentry>
-    for details) instead of the format string. Each structure should
-    reference one field of the entry to submit. The second argument
-    specifies the number of structures in the array.
-    <function>sd_journal_sendv()</function> is particularly useful to
-    submit binary objects to the journal where that is
-    necessary.</para>
+    <para><function>sd_journal_send()</function> may be used to submit structured log entries to the system journal. It
+    takes a series of format strings, each immediately followed by their associated parameters, terminated by
+    <constant>NULL</constant>. The strings passed should be of the format <literal>VARIABLE=value</literal>.  The
+    variable name must be in uppercase and consist only of characters, numbers and underscores, and may not begin with
+    an underscore. (All assignments that do not follow this syntax will be ignored.) The value can be of any size and
+    format. It is highly recommended to submit text strings formatted in the UTF-8 character encoding only, and submit
+    binary fields only when formatting in UTF-8 strings is not sensible. A number of well-known fields are defined, see
+    <citerefentry><refentrytitle>systemd.journal-fields</refentrytitle><manvolnum>7</manvolnum></citerefentry> for
+    details, but additional application defined fields may be used. A variable may be assigned more than one value per
+    entry. If this function is used, trailing whitespace is automatically removed from each formatted field.</para>
+
+    <para><function>sd_journal_sendv()</function> is similar to <function>sd_journal_send()</function> but takes an
+    array of <varname>struct iovec</varname> (as defined in <filename>uio.h</filename>, see <citerefentry
+    project='man-pages'><refentrytitle>readv</refentrytitle><manvolnum>3</manvolnum></citerefentry> for details)
+    instead of the format string. Each structure should reference one field of the entry to submit. The second argument
+    specifies the number of structures in the array.  <function>sd_journal_sendv()</function> is particularly useful to
+    submit binary objects to the journal where that is necessary. Note that this function wil not strip trailing
+    whitespace of the passed fields, but passes the specified data along unmodified. This is different from both
+    <function>sd_journal_print()</function> and <function>sd_journal_send()</function> described above, which are based
+    on format strings, and do strip trailing whitespace.</para>
 
     <para><function>sd_journal_perror()</function> is a similar to
     <citerefentry project='die-net'><refentrytitle>perror</refentrytitle><manvolnum>3</manvolnum></citerefentry>
@@ -174,8 +159,8 @@
     <programlisting>sd_journal_print(LOG_INFO, "Hello World, this is PID %lu!", (unsigned long) getpid());
 
 sd_journal_send("MESSAGE=Hello World, this is PID %lu!", (unsigned long) getpid(),
-    "PRIORITY=%i", LOG_INFO,
-    NULL);</programlisting>
+                "PRIORITY=%i", LOG_INFO,
+                NULL);</programlisting>
 
     <para>Note that these calls implicitly add fields for the source
     file, function name and code line where invoked. This is
diff --git a/src/journal/journal-send.c b/src/journal/journal-send.c
index 5e8a3e3200..440fba67ca 100644
--- a/src/journal/journal-send.c
+++ b/src/journal/journal-send.c
@@ -107,6 +107,13 @@ _public_ int sd_journal_printv(int priority, const char *format, va_list ap) {
         memcpy(buffer, "MESSAGE=", 8);
         vsnprintf(buffer+8, sizeof(buffer) - 8, format, ap);
 
+        /* Strip trailing whitespace, keep prefix whitespace. */
+        (void) strstrip(buffer);
+
+        /* Suppress empty lines */
+        if (isempty(buffer+8))
+                return 0;
+
         zero(iov);
         IOVEC_SET_STRING(iov[0], buffer);
         IOVEC_SET_STRING(iov[1], p);
@@ -158,6 +165,8 @@ _printf_(1, 0) static int fill_iovec_sprintf(const char *format, va_list ap, int
 
                 VA_FORMAT_ADVANCE(format, ap);
 
+                (void) strstrip(buffer); /* strip trailing whitespace, keep prefixing whitespace */
+
                 IOVEC_SET_STRING(iov[i++], buffer);
 
                 format = va_arg(ap, char *);
@@ -471,6 +480,13 @@ _public_ int sd_journal_printv_with_location(int priority, const char *file, con
         memcpy(buffer, "MESSAGE=", 8);
         vsnprintf(buffer+8, sizeof(buffer) - 8, format, ap);
 
+        /* Strip trailing whitespace, keep prefixing whitespace */
+        (void) strstrip(buffer);
+
+        /* Suppress empty lines */
+        if (isempty(buffer+8))
+                return 0;
+
         /* func is initialized from __func__ which is not a macro, but
          * a static const char[], hence cannot easily be prefixed with
          * CODE_FUNC=, hence let's do it manually here. */
diff --git a/src/shared/logs-show.c b/src/shared/logs-show.c
index 9351b85eed..d04728f505 100644
--- a/src/shared/logs-show.c
+++ b/src/shared/logs-show.c
@@ -489,7 +489,7 @@ static int output_verbose(
                         off = ANSI_NORMAL;
                 }
 
-                if (flags & OUTPUT_SHOW_ALL ||
+                if ((flags & OUTPUT_SHOW_ALL) ||
                     (((length < PRINT_CHAR_THRESHOLD) || flags & OUTPUT_FULL_WIDTH)
                      && utf8_is_printable(data, length))) {
                         fprintf(f, "    %s%.*s=", on, fieldlen, (const char*)data);
@@ -607,7 +607,7 @@ void json_escape(
         if (!(flags & OUTPUT_SHOW_ALL) && l >= JSON_THRESHOLD)
                 fputs("null", f);
 
-        else if (!utf8_is_printable(p, l)) {
+        else if (!(flags & OUTPUT_SHOW_ALL) && !utf8_is_printable(p, l)) {
                 bool not_first = false;
 
                 fputs("[ ", f);