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#ifdef __unix__
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/wait.h>
#include <unistd.h>
#include "xrdb_parse.h"
extern char **environ;
static int join_path(char buf[], int buf_size, const char *path, const char *name) {
const char *path_delim = strchr(path, ':');
if (!path_delim) {
path_delim = path + strlen(path);
}
const int path_len = path_delim - path, name_len = strlen(name);
if (buf_size < path_len + 1 + name_len + 1) return -1;
memcpy(buf, path, path_len);
buf[path_len] = '/';
memcpy(buf + path_len + 1, name, name_len + 1);
return 0;
}
static int xrdb_popen (int *pid_ptr) {
int fd[2];
if (pipe(fd) != 0) return -1;
int read_fd = fd[0];
int write_fd = fd[1];
int pid = fork();
if (pid == 0) {
close(read_fd);
dup2(write_fd, STDOUT_FILENO);
close(write_fd);
char *path = getenv("PATH");
char xrdb_filename[256];
while (path) {
char *xrgb_argv[3] = {"xrdb", "-query", NULL};
if (join_path(xrdb_filename, 256, path, "xrdb") == 0) {
execve(xrdb_filename, xrgb_argv, environ);
}
path = strchr(path, ':');
if (path) {
path++;
}
}
} else {
*pid_ptr = pid;
close(write_fd);
return read_fd;
}
return -1;
}
static int xrdb_try_dpi_match(const char *line, int len) {
if (len >= 8 && strncmp(line, "Xft.dpi:", 8) == 0) {
for (line += 8; *line && (*line == '\t' || *line == ' '); line++) { }
int dpi = 0;
for ( ; *line >= '0' && *line <= '9'; line++) {
dpi = dpi * 10 + ((int) (*line) - (int) '0');
}
return dpi;
}
return -1;
}
static void xrdb_complete_reading(int read_fd, char *buf, size_t buf_size) {
while (1) {
int nr = read(read_fd, buf, buf_size);
if (nr <= 0) return;
}
}
#define XRDB_READ_BUF_SIZE 256
static int xrdb_parse_for_dpi(int read_fd) {
char buf[XRDB_READ_BUF_SIZE];
char buf_remaining = 0;
while (1) {
int nr = read(read_fd, buf + buf_remaining, XRDB_READ_BUF_SIZE - buf_remaining);
if (nr > 0) {
const char * const buf_limit = buf + nr + buf_remaining;
char *line_start = buf;
while (line_start < buf_limit) {
char *nlptr = line_start;
while (nlptr < buf_limit && *nlptr != '\n') {
nlptr++;
}
if (nlptr < buf_limit) {
int dpi_read = xrdb_try_dpi_match(line_start, nlptr - line_start);
if (dpi_read > 0) {
xrdb_complete_reading(read_fd, buf, XRDB_READ_BUF_SIZE);
return dpi_read;
}
/* doesn't match: position after newline to search again */
line_start = nlptr + 1;
} else {
/* No newline found: copy the remaining part at the beginning of buf
and read again from file descriptor. */
buf_remaining = buf_limit - line_start;
if (buf_remaining >= XRDB_READ_BUF_SIZE) {
/* Line is too long for the buffer: skip. */
buf_remaining = 0;
} else {
memmove(buf, line_start, buf_remaining);
}
break;
}
}
} else {
if (nr == 0 && buf_remaining > 0) {
int dpi_read = xrdb_try_dpi_match(buf, buf_remaining);
if (dpi_read > 0) {
return dpi_read;
}
}
break;
}
}
return -1;
}
int xrdb_find_dpi() {
int xrdb_pid;
int read_fd = xrdb_popen(&xrdb_pid);
if (read_fd >= 0) {
int dpi_read = xrdb_parse_for_dpi(read_fd);
int child_status;
waitpid(xrdb_pid, &child_status, 0);
close(read_fd);
return dpi_read;
}
return -1;
}
#endif
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