shithub: moonfish

ref: 401af6dfdde75f7e37b5f4874e99776d9ea1de67
dir: /tools/utils.c/

/* moonfish is licensed under the AGPL (v3 or later) */
/* copyright 2023, 2024 zamfofex */

#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <fcntl.h>

#include "tools.h"

static int moonfish_fork(char *argv0, char **argv, int *in_fd, int *out_fd)
{
	int p1[2], p2[2];
	int pid, fd;
	
	if (pipe(p1) == -1) return 1;
	if (pipe(p2) == -1) return 1;
	
	pid = fork();
	if (pid == -1) return 1;
	
	if (pid)
	{
		*in_fd = p1[1];
		*out_fd = p2[0];
		close(p1[0]);
		close(p2[1]);
		return 0;
	}
	
	fd = open("/dev/null", O_RDONLY);
	if (fd < 0)
	{
		fprintf(stderr, "%s: %s: %s\n", argv0, argv[0], strerror(errno));
		exit(1);
	}
	
	dup2(p1[0], 0);
	dup2(p2[1], 1);
	dup2(p2[1], 2);
	
	close(p1[0]);
	close(p1[1]);
	close(p2[0]);
	close(p2[1]);
	
	execvp(argv[0], argv);
	fprintf(stderr, "%s: %s: %s\n", argv0, argv[0], strerror(errno));
	
	exit(1);
}

void moonfish_spawn(char *argv0, char **argv, FILE **in, FILE **out)
{
	int in_fd, out_fd;
	
	if (moonfish_fork(argv0, argv, &in_fd, &out_fd))
	{
		perror(argv0);
		exit(1);
	}
	
	*in = fdopen(in_fd, "w");
	if (*in == NULL)
	{
		perror(argv0);
		exit(1);
	}
	
	*out = fdopen(out_fd, "r");
	if (*out == NULL)
	{
		perror(argv0);
		exit(1);
	}
	
	errno = 0;
	if (setvbuf(*in, NULL, _IOLBF, 0))
	{
		if (errno) perror(argv0);
		exit(1);
	}
	
	errno = 0;
	if (setvbuf(*out, NULL, _IOLBF, 0))
	{
		if (errno) perror(argv0);
		exit(1);
	}
}

char *moonfish_next(FILE *file)
{
	static char line[2048];
	
	if (fgets(line, sizeof line, file) == NULL)
		return NULL;
	return line;
}

char *moonfish_wait(FILE *file, char *name)
{
	char *line, *arg;
	
	for (;;)
	{
		line = moonfish_next(file);
		if (line == NULL) exit(1);
		
		arg = strtok(line, "\r\n\t ");
		if (arg == NULL) continue;
		if (!strcmp(line, name))
			return strtok(NULL, "\r\n\t ");
	}
}