PMDAOPENLOG(3)

💖 PMDAOPENLOG 💖

okay bestie, welcome to PMDAOPENLOG(3), part of the Library Functions Manual — yes it's a section 3 page, yes we're gonna make it cute, yes every single fact is staying. 🎀

✨ NAME ✨

pmdaOpenLog — redirect stderr to a logfile

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🌸 C SYNOPSIS 🌸

#include <pcp/pmapi.h>
#include <pcp/pmda.h>

void pmdaOpenLog(pmdaInterface * dispatch);

cc ... -lpcp_pmda -lpcp

🦋 DESCRIPTION 🦋

So what does this lil function do? pmdaOpenLog redirects stderr to the logfile specified in the dispatch structure — and that logfile got set by the previous call to pmdaDaemon(3) or pmdaGetOpt(3). Like, it's the glow-up your error output has been waiting for. ✨

The first line of the log file will detail the name of the calling process, the host the process is running on, and the current time. Receipts, basically. 📝

On top of that, the log is appended with the exit time of the process by a routine registered with atexit(3). So it says hi and it says bye. iconic behavior honestly. 👑

💅 CAVEAT 💅

The PMDA must be using PMDA_INTERFACE_2 or later, as specified in the call to pmdaDSO(3) or pmdaDaemon(3). no cap, this is not optional, if you're on an older interface it's giving ✨not supported✨.

🌈 PCP ENVIRONMENT 🌈

Environment variables with the prefix PCP_ are used to parameterize the file and directory names used by PCP. On each installation, the file /etc/pcp.conf contains the local values for these variables.

The $PCP_CONF variable may be used to specify an alternative configuration file, as described in pcp.conf(5). 📂

Values for these variables may be obtained programmatically using the pmGetConfig(3) function. iykyk. 🫶

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⭐ SEE ALSO ⭐

• pmcd(1)
• atexit(2)
• PMAPI(3)
• PMDA(3)
• pmdaDaemon(3)
• pmdaGetOpt(3)

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and that's the whole page bestie!! this one shipped as part of Performance Co-Pilot (that's the PCP girlies 💜), and the page itself is dated/labelled PMDAOPENLOG(3) — so yeah, same name top and bottom, we love a symmetrical moment. mwah, go log something 💖✨