logging: rework _output() function
This patch reworks _output() to handle snprintf() return value
appropriately and to use one single buffer to build the logging
string, instead of four.
diff --git a/src/logging.c b/src/logging.c
index 7fabfcb..526b39e 100644
--- a/src/logging.c
+++ b/src/logging.c
@@ -143,29 +143,19 @@
unsigned int level, char *file, int line, int cont,
const char *format, va_list ap)
{
- char col[30];
- char sub[30];
- char tim[30];
char buf[4096];
- char final[4096];
-
- /* prepare the data */
- col[0] = '\0';
- sub[0] = '\0';
- tim[0] = '\0';
- buf[0] = '\0';
+ int ret, len = 0, offset = 0, rem = sizeof(buf);
/* are we using color */
if (target->use_color) {
const char *c = color(subsys);
if (c) {
- snprintf(col, sizeof(col), "%s", color(subsys));
- col[sizeof(col)-1] = '\0';
+ ret = snprintf(buf + offset, rem, "%s", color(subsys));
+ if (ret < 0)
+ goto err;
+ OSMO_SNPRINTF_RET(ret, rem, offset, len);
}
}
- vsnprintf(buf, sizeof(buf), format, ap);
- buf[sizeof(buf)-1] = '\0';
-
if (!cont) {
if (target->print_timestamp) {
char *timestr;
@@ -173,17 +163,30 @@
tm = time(NULL);
timestr = ctime(&tm);
timestr[strlen(timestr)-1] = '\0';
- snprintf(tim, sizeof(tim), "%s ", timestr);
- tim[sizeof(tim)-1] = '\0';
+ ret = snprintf(buf + offset, rem, "%s ", timestr);
+ if (ret < 0)
+ goto err;
+ OSMO_SNPRINTF_RET(ret, rem, offset, len);
}
- snprintf(sub, sizeof(sub), "<%4.4x> %s:%d ", subsys, file, line);
- sub[sizeof(sub)-1] = '\0';
+ ret = snprintf(buf + offset, rem, "<%4.4x> %s:%d ",
+ subsys, file, line);
+ if (ret < 0)
+ goto err;
+ OSMO_SNPRINTF_RET(ret, rem, offset, len);
}
+ ret = vsnprintf(buf + offset, rem, format, ap);
+ if (ret < 0)
+ goto err;
+ OSMO_SNPRINTF_RET(ret, rem, offset, len);
- snprintf(final, sizeof(final), "%s%s%s%s%s", col, tim, sub, buf,
- target->use_color ? "\033[0;m" : "");
- final[sizeof(final)-1] = '\0';
- target->output(target, level, final);
+ ret = snprintf(buf + offset, rem, "%s",
+ target->use_color ? "\033[0;m" : "");
+ if (ret < 0)
+ goto err;
+ OSMO_SNPRINTF_RET(ret, rem, offset, len);
+err:
+ buf[sizeof(buf)-1] = '\0';
+ target->output(target, level, buf);
}