File-specific system command execution mapping implementation. More...

#include "lcmd.h"
#include <assert.h>
#include <errno.h>
#include <regex.h>
#include <stdatomic.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/wait.h>
#include <sysexits.h>
#include <unistd.h>
#include "cJSON/cJSON.h"
#include "jemalloc/jemalloc.h"
#include "fd.h"
#include "je.h"
#include "log.h"
#include "tm.h"

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Functions
static void	str_free (str_set_inner_item *str)
	Frees a dynamically allocated string.

static void	lcmdfree (struct lcmdset_s *cmd)
	Frees the memory allocated for a single command set entry struct.

void	lcmdfree_r (lcmdset_set *cs)
	Iterates and frees all memory allocated by the command set array.

static char *	fsreadstr (const char *fp)
	Reads the contents of the file described by filepath `fp` into a dynamically allocated buffer returned by the function.

static str_set *	lcmdcopycmds (const cJSON *arr)
	Duplicates a cJSON array of strings into a str_set. Non-string entries will print an error message and cause the entry to be NULL.

static int	lcmdparseflags (const cJSON *item)
	Parses a cJSON array of strings into a set of file event bit flags. Non-string entries are ignored. Unrecognized string entries will log an error message. Accepted strings are "new", "mod", and "del" which map to `LCTRIG_NEW`, `LCTRIG_MOD`, and `LCTRIG_DEL` respectively.

static int	lcmdparseone (const cJSON obj, struct lcmdset_s cmd, const int id)
	Populates a single command struct by parsing the fields of the provided cJSON object.

lcmdset_set *	lcmdparse (const char *fp)
	Parses the provided file path and populates an array of command sets. The file must be a valid JSON file containing an array of objects. Each object must contain the following keys:

static bool	lcmdmatch (regex_set fpatterns, const char fp)
	Checks if the provided filepath matches any of the compiled regex patterns in the provided array.

bool	lcmdmatchany (lcmdset_set cs, const char fp)
	Checks if the provided file path matches any of the file patterns in the command set.

static int	lcmdfailed (const char *src, const int st)
	Checks if the waitpid(2)-style int described by the wait status `st` failed due to an exit code or signal termination. If so, an appropriate log message is printed using the source description `src`.

static int	lcmdinvoke (const char cmd, const char fp, struct fdset_s fds, const int flags, _Atomic uint64_t *msspent)
	Invokes a string `cmd` as a system command using `system(3)` in a forked/child process. The file path of `node` is set as an environment variable for use in the command. File descriptor set `fds` is used to optionally redirect stdout and stderr of the child command processes.

int	lcmdexec (lcmdset_set cs, const char fp, const struct fdset_s fds, int flags)
	Sequentially iterates the command set and executes the configured system commands on the provided file node if the trigger flags and file patterns match.

Detailed Description

File-specific system command execution mapping implementation.

Function Documentation

◆ fsreadstr()

static char * fsreadstr ( const char * fp )

static

Reads the contents of the file described by filepath fp into a dynamically allocated buffer returned by the function.

Parameters

fp	The filepath to read

Returns: If successful, a pointer to a dynamically allocated buffer of the file's null terminated contents. The caller is responsible for freeing the buffer.

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◆ lcmdcopycmds()

static str_set * lcmdcopycmds ( const cJSON * arr )

static

Duplicates a cJSON array of strings into a str_set. Non-string entries will print an error message and cause the entry to be NULL.

Parameters

arr	cJSON array of strings

Returns: NULL if a string could not be duplicated, or the set could not be allocated. Otherwise, a str_set is returned containing the duplicated strings.

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◆ lcmdexec()

int lcmdexec	(	lcmdset_set *	cs,
		const char *	fp,
		struct fdset_s	fds,
		int	flags
	)

Sequentially iterates the command set and executes the configured system commands on the provided file node if the trigger flags and file patterns match.

Parameters

cs	The command set array to filter and execute
fp	The file path to match against the command set
fds	The file descriptor set to use for stdout/stderr redirection
flags	The trigger flags to match, see `LCTRIG_*`. If `LCTOPT_VERBOSE` is set, the commands will be printed to stdout before execution. If `LCTOPT_TRACE` is set, the true/false match result for each command set will be printed to stdout.

Returns: 0 if successful, otherwise the first non-zero return value from system(3) is returned.

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◆ lcmdfailed()

static int lcmdfailed	(	const char *	src,
		const int	st
	)

static

Checks if the waitpid(2)-style int described by the wait status st failed due to an exit code or signal termination. If so, an appropriate log message is printed using the source description src.

Parameters

src	The source description of the child process
st	The wait status of the child process

Returns: 1 if the value exited or was signaled, otherwise 0.

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◆ lcmdfree()

static void lcmdfree ( struct lcmdset_s * cmd )

static

Frees the memory allocated for a single command set entry struct.

Parameters

cmd	Command set entry to free

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◆ lcmdfree_r()

void lcmdfree_r ( lcmdset_set * cs )

Iterates and frees all memory allocated by the command set array.

Parameters

cs	The command set array to free

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◆ lcmdinvoke()

static int lcmdinvoke	(	const char *	cmd,
		const char *	fp,
		struct fdset_s	fds,
		const int	flags,
		_Atomic uint64_t *	msspent
	)

static

Invokes a string cmd as a system command using system(3) in a forked/child process. The file path of node is set as an environment variable for use in the command. File descriptor set fds is used to optionally redirect stdout and stderr of the child command processes.

Parameters

cmd	The command string to execute
fp	The file path to assign to the FILEPATH environment variable
fds	The file descriptor set to use for stdout/stderr redirection
flags	Bit flags for controlling command execution. If the `LCTOPT_VERBOSE` flag is set, the command will be printed to stdout before execution. If the `LCTOPT_TRACE` flag is set, debug information regarding the eligibility of any encountered file path will be printed to stdout.
msspent	Optional pointer to a uint64_t value to which the time spent executing the command (in milliseconds) will be added.

Returns: 0 if successful, otherwise -1 to indicate an error.

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◆ lcmdmatch()

static bool lcmdmatch	(	regex_set *	fpatterns,
		const char *	fp
	)

static

Checks if the provided filepath matches any of the compiled regex patterns in the provided array.

Parameters

fpatterns	Array of compiled regex patterns
fp	Filepath to match

Returns: True if the filepath matches any of the patterns, otherwise false.

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◆ lcmdmatchany()

bool lcmdmatchany	(	lcmdset_set *	cs,
		const char *	fp
	)

Checks if the provided file path matches any of the file patterns in the command set.

Parameters

cs	The command set array to filter
fp	The file path to match

Returns: true if the file path matches any file pattern, otherwise false

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◆ lcmdparse()

lcmdset_set * lcmdparse ( const char * fp )

Parses the provided file path and populates an array of command sets. The file must be a valid JSON file containing an array of objects. Each object must contain the following keys:

on: An array of trigger flags to match
patterns: An array of file patterns to match
commands: An array of system commands to execute The on array must contain one or more of the following strings:
new: Trigger on new files
mod: Trigger on modified files
del: Trigger on deleted files The patterns array must contain one or more strings that are used to match the file path. The commands array must contain one or more strings that are passed to system(3) for execution.
Parameters

fp The file path to parse

Returns
An array of command sets if successful, otherwise NULL.

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◆ lcmdparseflags()

static int lcmdparseflags ( const cJSON * item )

static

Parses a cJSON array of strings into a set of file event bit flags. Non-string entries are ignored. Unrecognized string entries will log an error message. Accepted strings are "new", "mod", and "del" which map to LCTRIG_NEW, LCTRIG_MOD, and LCTRIG_DEL respectively.

Parameters

item	cJSON array of strings

Returns: Bit flags representing the file event types, or 0 if no flags were correctly parsed.

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◆ lcmdparseone()

static int lcmdparseone	(	const cJSON *	obj,
		struct lcmdset_s *	cmd,
		const int	id
	)

static

Populates a single command struct by parsing the fields of the provided cJSON object.

Parameters

obj	cJSON object containing the command data
cmd	Struct to populate with parsed command data
id	Command set index for naming purposes

Returns: 0 if successful, otherwise non-zero to indicate an error.

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◆ str_free()

static void str_free ( str_set_inner_item * str )

static

Frees a dynamically allocated string.

Parameters

str	Pointer to the string to free

Note: This function is intended for use with str_set_for_each, which requires a function that takes a pointer to the inner item type.

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Functions

Detailed Description

Function Documentation

◆ fsreadstr()

◆ lcmdcopycmds()

◆ lcmdexec()

◆ lcmdfailed()

◆ lcmdfree()

◆ lcmdfree_r()

◆ lcmdinvoke()

◆ lcmdmatch()

◆ lcmdmatchany()

◆ lcmdparse()

◆ lcmdparseflags()

◆ lcmdparseone()

◆ str_free()