[PATCH 3/5] logging: rework _output() function

From: Pablo Neira Ayuso &lt;pablo(a)gnumonks.org&gt; This patch reworks _output() to handle snprintf() return value appropriately and to use one single buffer to build the logging string, instead of four. --- src/logging.c | 51 +++++++++++++++++++++++++++------------------------ 1 files changed, 27 insertions(+), 24 deletions(-) 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 @@ static void _output(struct log_target *target, unsigned int subsys, 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 @@ static void _output(struct log_target *target, unsigned int subsys, 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); } -- 1.7.2.3