From: Eric Covener <covener@apache.org>
Date: Fri, 6 Jan 2023 23:46:35 +0000 (+0000)
Subject: add -T flag to truncate rotated logs only
X-Git-Tag: 2.5.0-alpha2-ci-test-only~168
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d0eac89e98e5c0acc6f73080521589d8f74f5d9c;p=thirdparty%2Fapache%2Fhttpd.git

add -T flag to truncate rotated logs only

for strftime formats that will loop back on themselves, like
day of month or weekday name.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1906433 13f79535-47bb-0310-9956-ffa450edef68
---

diff --git a/changes-entries/rotatlogs_truncate_rotated.txt b/changes-entries/rotatlogs_truncate_rotated.txt
new file mode 100644
index 00000000000..2cc69366ea8
--- /dev/null
+++ b/changes-entries/rotatlogs_truncate_rotated.txt
@@ -0,0 +1,2 @@
+  *) rotatelogs: Add -T flag to allow subsequent rotated logfiles to be
+     truncated without the initial logfile being truncated.  [Eric Covener]
diff --git a/docs/manual/programs/rotatelogs.xml b/docs/manual/programs/rotatelogs.xml
index df5956cb09c..ed3d9aa9084 100644
--- a/docs/manual/programs/rotatelogs.xml
+++ b/docs/manual/programs/rotatelogs.xml
@@ -111,6 +111,13 @@ the filename, however format strings containing '%' characters
 will be respected.
 </dd>
 
+<dt><code>-T</code></dt>
+<dd>Causes all but the initial logfile to be truncated when opened.
+This is useful when the format string contains something that will
+loop around, such as the day of the month.
+</dd>
+
+
 <dt><code>-v</code></dt>
 <dd>Produce verbose output on STDERR. The output contains
 the result of the configuration parsing, and all file open and
@@ -263,6 +270,18 @@ an offset.</dd>
      in this scenario that a separate process (such as tail) would
      process the file in real time.</p>
 
+<example>
+<highlight language="config">
+     CustomLog "|bin/rotatelogs -T /var/log/logfile.%d 86400" common
+</highlight>
+</example>
+
+<p>If the server is started (or restarted) on the first of the month, this 
+appends to <code>/var/log/logfile.01</code>.  When a log entry is written on the
+second of the month, <code>/var/log/logfile.02</code> is truncated and new entries
+will be added to the top. This example keeps approximately 1 months worth of 
+logs without external maintenance.</p>
+
 </section>
 
 <section id="portability"><title>Portability</title>
diff --git a/support/rotatelogs.c b/support/rotatelogs.c
index 5430f9e2e3c..fb48ae789ca 100644
--- a/support/rotatelogs.c
+++ b/support/rotatelogs.c
@@ -65,6 +65,7 @@ struct rotate_config {
     int echo;
     char *szLogRoot;
     int truncate;
+    int truncate_rotated_only;
     const char *linkfile;
     const char *postrotate_prog;
 #if APR_FILES_AS_SOCKETS
@@ -109,9 +110,9 @@ static void usage(const char *argv0, const char *reason)
     }
     fprintf(stderr,
 #if APR_FILES_AS_SOCKETS
-            "Usage: %s [-v] [-l] [-L linkname] [-p prog] [-f] [-D] [-t] [-e] [-c] [-n number] <logfile> "
+            "Usage: %s [-vlfDtTec] [-L linkname] [-p prog] [-n number] <logfile> "
 #else
-            "Usage: %s [-v] [-l] [-L linkname] [-p prog] [-f] [-D] [-t] [-e] [-n number] <logfile> "
+            "Usage: %s [-vlfDtTe] [-L linkname] [-p prog] [-n number] <logfile> "
 #endif
             "{<rotation time in seconds>|<rotation size>(B|K|M|G)} "
             "[offset minutes from UTC]\n\n",
@@ -145,6 +146,7 @@ static void usage(const char *argv0, const char *reason)
             "  -f       Force opening of log on program start.\n"
             "  -D       Create parent directories of log file.\n" 
             "  -t       Truncate logfile instead of rotating, tail friendly.\n"
+            "  -T       Truncate logfiles opened for rotation, but not the initial logfile.\n"
             "  -e       Echo log to stdout for further processing.\n"
 #if APR_FILES_AS_SOCKETS
             "  -c       Create log even if it is empty.\n"
@@ -379,6 +381,7 @@ static void doRotate(rotate_config_t *config, rotate_status_t *status)
     struct logfile newlog;
     int thisLogNum = -1;
     int oldreason = status->rotateReason;
+    int truncate = config->truncate;
 
     /* Retrieve local-time-adjusted-Unix-time. */
     now = get_now(config, &offset);
@@ -458,8 +461,17 @@ static void doRotate(rotate_config_t *config, rotate_status_t *status)
     if (config->verbose) {
         fprintf(stderr, "Opening file %s\n", newlog.name);
     }
-    rv = apr_file_open(&newlog.fd, newlog.name, APR_WRITE | APR_CREATE | APR_APPEND
-                       | (config->truncate || (config->num_files > 0 && status->current.fd) ? APR_TRUNCATE : 0), 
+
+    if (!truncate) {
+        /* -n and -T truncate subsequent files only. */
+        if (status->current.fd &&
+               (config->num_files > 0 || config->truncate_rotated_only)) {
+            truncate = 1;
+        }
+    }
+    rv = apr_file_open(&newlog.fd, newlog.name,
+                       APR_WRITE | APR_CREATE | APR_APPEND
+                       | (truncate ? APR_TRUNCATE : 0),
                        APR_OS_DEFAULT, newlog.pool);
     if (rv == APR_SUCCESS) {
         /* Handle post-rotate processing. */
@@ -597,9 +609,9 @@ int main (int argc, const char * const argv[])
     apr_pool_create(&status.pool, NULL);
     apr_getopt_init(&opt, status.pool, argc, argv);
 #if APR_FILES_AS_SOCKETS
-    while ((rv = apr_getopt(opt, "lL:p:fDtvecn:", &c, &opt_arg)) == APR_SUCCESS) {
+    while ((rv = apr_getopt(opt, "lL:p:fDtTvecn:", &c, &opt_arg)) == APR_SUCCESS) {
 #else
-    while ((rv = apr_getopt(opt, "lL:p:fDtven:", &c, &opt_arg)) == APR_SUCCESS) {
+    while ((rv = apr_getopt(opt, "lL:p:fDtTven:", &c, &opt_arg)) == APR_SUCCESS) {
 #endif
         switch (c) {
         case 'l':
@@ -624,6 +636,9 @@ int main (int argc, const char * const argv[])
         case 't':
             config.truncate = 1;
             break;
+        case 'T':
+            config.truncate_rotated_only = 1;
+            break;
         case 'v':
             config.verbose = 1;
             break;