external_tool.cpp File Reference

Implementation of the external-tool helpers. More...

#include "postgres.h"
#include "provsql_utils.h"
#include "miscadmin.h"
#include <signal.h>
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <unistd.h>
#include <sys/wait.h>
#include "external_tool.h"
#include "ToolRegistry.h"
#include "provsql_config.h"
#include <string>
#include <unordered_map>

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Functions
static int	run_in_own_pgroup (const std::string &cmdline)
int	run_external_tool (const std::string &cmdline)
	Run a shell command line in its own process group, optionally extending PATH, interruptible by query cancel / statement_timeout.
std::string	find_external_tool (const std::string &name)
	Locate an external tool by name.
std::string	format_external_tool_status (int rv, const std::string &tool)
	Decode a system() return value into a human-readable message.
bool	toolAvailable (const provsql::ToolRecord &rec)
	True iff a registry tool can currently be used.

Variables
static const char *	DEFAULT_PATH

Detailed Description

Implementation of the external-tool helpers.

Reads the provsql.tool_search_path GUC (exposed as provsql_tool_search_path) and uses it both to extend $PATH around system() and to drive the pre-flight find_external_tool() lookup.

Definition in file external_tool.cpp.

Function Documentation

find_external_tool()

std::string find_external_tool

(

const std::string &

name

)

Locate an external tool by name.

Searches provsql_tool_search_path (colon-separated), then $PATH, for an executable file matching name (via access(X_OK)). Returns the full path on success, or the empty string if nothing matches.

Names containing a slash are treated as paths and tested directly without any directory walk.

Parameters

name	Bare executable name (e.g. "d4") or a path.

Returns

Resolved path, or "" if name is not found.

Definition at line 150 of file external_tool.cpp.

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format_external_tool_status()

std::string format_external_tool_status	(	int	rv,
		const std::string &	tool )

Decode a system() return value into a human-readable message.

Parameters

rv	Return value from system() (or run_external_tool()).
tool	Tool name, used as the message subject.

Returns

Empty string when rv indicates success; otherwise a message that distinguishes "not found at runtime" (shell exit 127), "not executable" (126), "killed by signal N", "exited with status N", or system() itself failing.

Definition at line 197 of file external_tool.cpp.

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run_external_tool()

int run_external_tool

(

const std::string &

cmdline

)

Run a shell command line in its own process group, optionally extending PATH, interruptible by query cancel / statement_timeout.

If provsql_tool_search_path is non-empty, it is prepended (with :) to $PATH for the duration and restored afterwards. The command runs via /bin/sh -c as a process-group leader; while it runs the parent polls for a pending cancel/terminate and, if one fires, SIGKILLs the whole group (reaching tools that fork workers) and lets CHECK_FOR_INTERRUPTS raise it.

Parameters

cmdline

Shell command line, passed verbatim to /bin/sh -c.

Returns

A wait(2) status (decode with WIFEXITED etc., as a system() return), or -1 if fork failed.

Definition at line 113 of file external_tool.cpp.

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run_in_own_pgroup()

int run_in_own_pgroup ( const std::string & cmdline )

static

Definition at line 57 of file external_tool.cpp.

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toolAvailable()

bool toolAvailable

(

const provsql::ToolRecord &

rec

)

True iff a registry tool can currently be used.

A kcmcp record needs a configured endpoint (no live connect probe, mirroring how a CLI tool only needs its binary on PATH). A cli record needs its binary (when set) and every dependency to resolve on the backend's PATH via find_external_tool. This is the single availability predicate consulted both by the compile/wmc tool selection and by the provsql.tools view.

Definition at line 218 of file external_tool.cpp.

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Variable Documentation

DEFAULT_PATH

const char* DEFAULT_PATH

static

Initial value:

                           =
"/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"

Definition at line 36 of file external_tool.cpp.