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-rw-r--r--adjbacklight.c327
1 files changed, 195 insertions, 132 deletions
diff --git a/adjbacklight.c b/adjbacklight.c
index 9fe68c1..6fa0066 100644
--- a/adjbacklight.c
+++ b/adjbacklight.c
@@ -226,22 +226,187 @@ handle_device(const char *device, int get, int set, double adj, int inc, const c
}
+static void
+check_permissions(void)
+{
+ long int ngroups_max;
+ gid_t *groups;
+ int ngroups;
+ struct group *videogrp = getgrnam("video");
+
+ if (!getuid())
+ return;
+
+ if (!videogrp && errno && errno != ENOENT && errno != ESRCH && errno != EPERM) {
+ /* Note, glibc sets errno to EIO if the group does not exist,
+ * this is the not the specified behavour by either POSIX or
+ * glibc, and it would be a security issue to treat it as OK.
+ * Additionally, EBADF is not treated as OK. */
+ fprintf(stderr, "%s: getgrnam video: %s\n", argv0, strerror(errno));
+ exit(1);
+ } else if (videogrp) {
+ ngroups_max = sysconf(_SC_NGROUPS_MAX) + 1;
+ if (ngroups_max < 0 || ngroups_max > INT_MAX - 1) {
+ fprintf(stderr, "%s: sysconf _SC_NGROUPS_MAX: %s\n", argv0, strerror(errno));
+ exit(1);
+ }
+ groups = alloca((size_t)ngroups_max * sizeof(*groups));
+ ngroups = getgroups((int)ngroups_max, groups);
+ if (ngroups < 0) {
+ fprintf(stderr, "%s: getgroups: %s\n", argv0, strerror(errno));
+ exit(1);
+ }
+ while (ngroups--)
+ if (groups[ngroups] == videogrp->gr_gid)
+ break;
+ if (ngroups < 0) {
+ fprintf(stderr, "%s: only root and members of the group 'video' may run this command\n", argv0);
+ exit(1);
+ }
+ }
+}
+
+
+static int
+parse_set_argument(const char *str, char *set_prefix, double *set_value, const char **set_suffix)
+{
+ *set_prefix = '=';
+
+ if (*str == '+' || *str == '-') {
+ *set_prefix = *str;
+ str++;
+ }
+ if (!isdigit(*str) && *str != '.')
+ return -1;
+ errno = 0;
+ *set_value = strtod(str, (void *)set_suffix);
+ if (errno || *set_value < 0) {
+ fprintf(stderr, "%s: strtod %s: %s\n", argv0, str, strerror(errno));
+ exit(1);
+ }
+ if (**set_suffix && strcmp(*set_suffix, "%") && strcmp(*set_suffix, "%%"))
+ usage();
+ if (*set_prefix == '-') {
+ *set_value = -*set_value;
+ *set_prefix = '+';
+ }
+ return 0;
+}
+
+
+static int
+init_terminal(pid_t *pid, struct termios *saved_stty)
+{
+ struct termios stty;
+ struct winsize win;
+ int i;
+
+ printf("\n\n");
+ printf("If the program is abnormally aborted the may be some residual\n");
+ printf("effects on the terminal. the following commands should reset it:\n");
+ printf("\n");
+ printf(" stty sane\n");
+ printf(" printf '\\ec'\n");
+ printf("\n");
+ printf("\n\n\n\n");
+
+ /* Get the size of the terminal */
+ if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &win) == -1)
+ fprintf(stderr, "%s: ioctl <stdout> TIOCGWINSZ: %s\n", argv0, strerror(errno));
+ else
+ cols = win.ws_col;
+
+ line = malloc((size_t)cols * 3);
+ space = malloc((size_t)cols);
+ if (!line || !space) {
+ fprintf(stderr, "%s: malloc: %s\n", argv0, strerror(ENOMEM));
+ exit(1);
+ }
+ for (i = 0; i < cols; i++) {
+ line[i * 3 + 0] = (char)(0xE2);
+ line[i * 3 + 1] = (char)(0x94);
+ line[i * 3 + 2] = (char)(0x80);
+ }
+ memset(space, ' ', (size_t)cols);
+ space[cols - 1] = '\0';
+ line[(cols - 2) * 3] = '\0';
+
+ /* stty -icanon -echo */
+ if (tcgetattr(STDIN_FILENO, &stty)) {
+ fprintf(stderr, "%s: tcgetattr <stdin>: %s\n", argv0, strerror(errno));
+ exit(1);
+ }
+ *saved_stty = stty;
+ stty.c_lflag &= (tcflag_t)~(ICANON | ECHO);
+ if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &stty)) {
+ fprintf(stderr, "%s: tcsetattr <stdin>: %s\n", argv0, strerror(errno));
+ exit(1);
+ }
+
+ /* Hide cursor */
+ printf("%s", "\033[?25l");
+ fflush(stdout);
+
+ /* Fork to diminish risk of unclean exit */
+ *pid = fork();
+ if (*pid == (pid_t)-1) {
+ fprintf(stderr, "%s: fork: %s\n", argv0, strerror(errno));
+ } else if (*pid) {
+ waitpid(*pid, NULL, 0);
+ return -1;
+ }
+
+ return 0;
+}
+
+
+static int
+update(int argc, char *argv[], int all, int get, char *set, int set_prefix, double set_value, const char *set_suffix)
+{
+ DIR *dir;
+ struct dirent *ent;
+ int any = argc;
+
+ if (argc) {
+ for (; *argv; argv++) {
+ if (strchr(*argv, '/'))
+ *argv = strrchr(*argv, '/');
+ handle_device(*argv, get, !!set, set_value, set_prefix == '+', set_suffix);
+ }
+ } else {
+ if ((dir = opendir(BACKLIGHT_DIR))) {
+ while ((ent = readdir(dir))) {
+ if (all || strstr(ent->d_name, "acpi_video") == ent->d_name) {
+ if (*ent->d_name && *ent->d_name != '.') {
+ handle_device(ent->d_name, get, !!set, set_value, set_prefix == '+', set_suffix);
+ any = 1;
+ }
+ }
+ }
+ closedir(dir);
+ }
+ if (!any)
+ fprintf(stderr, "%s: cannot find any backlight devices\n", argv0);
+ }
+
+ return any;
+}
+
+
int
main(int argc, char *argv[])
{
int all = 0;
int get = 0;
- char* set = NULL;
+ char *set = NULL;
char set_prefix = '=';
double set_value = 0;
- char* set_suffix = NULL;
- struct winsize win;
- struct termios saved_stty;
- struct termios stty;
+ const char *set_suffix = NULL;
pid_t pid = -1;
- DIR *dir;
- struct dirent *ent;
- int any = 0;
+ struct termios saved_stty;
+ int isinteractive = 0;
+ size_t size = 0;
+ ssize_t len;
ARGBEGIN {
case 'a':
@@ -261,139 +426,37 @@ main(int argc, char *argv[])
usage();
/* Parse -s argument */
- if (set) {
- if (*set == '+' || *set == '-') {
- set_prefix = *set;
- set++;
- }
- if (!isdigit(*set) && *set != '.')
- usage();
- errno = 0;
- set_value = strtod(set, &set_suffix);
- if (errno || set_value < 0) {
- fprintf(stderr, "%s: strtod %s: %s\n", argv0, set, strerror(errno));
- return 1;
- }
- if (*set_suffix && strcmp(set_suffix, "%") && strcmp(set_suffix, "%%"))
- usage();
- if (set_prefix == '-') {
- set_value = -set_value;
- set_prefix = '+';
- }
- }
+ if (set && parse_set_argument(set, &set_prefix, &set_value, &set_suffix))
+ usage();
/* Check permissions (important because the program is installed with set-uid) */
- if (getuid()) {
- struct group *videogrp = getgrnam("video");
- if (!videogrp && errno && errno != ENOENT && errno != ESRCH && errno != EPERM) {
- /* Note, glibc sets errno to EIO if the group does not exist,
- * this is the not the specified behavour by either POSIX or
- * glibc, and it would be a security issue to treat it as OK.
- * Additionally, EBADF is not treated as OK. */
- fprintf(stderr, "%s: getgrnam video: %s\n", argv0, strerror(errno));
- return 1;
- } else if (videogrp) {
- long ngroups_max = sysconf(_SC_NGROUPS_MAX) + 1;
- gid_t *groups;
- int ngroups;
- if (ngroups_max < 0 || ngroups_max > INT_MAX - 1) {
- fprintf(stderr, "%s: sysconf _SC_NGROUPS_MAX: %s\n", argv0, strerror(errno));
- return 1;
- }
- groups = alloca((size_t)ngroups_max * sizeof(*groups));
- ngroups = getgroups((int)ngroups_max, groups);
- if (ngroups < 0) {
- fprintf(stderr, "%s: getgroups: %s\n", argv0, strerror(errno));
- return 1;
- }
- while (ngroups--)
- if (groups[ngroups] == videogrp->gr_gid)
- break;
- if (ngroups < 0) {
- fprintf(stderr, "%s: only root and members of the group 'video' may run this command\n", argv0);
- return 1;
- }
- }
- }
+ check_permissions();
if (!get && !set) {
- int i;
- printf("\n\n");
- printf("If the program is abnormally aborted the may be some residual\n");
- printf("effects on the terminal. the following commands should reset it:\n");
- printf("\n");
- printf(" stty sane\n");
- printf(" printf '\\ec'\n");
- printf("\n");
- printf("\n\n\n\n");
-
- /* Get the size of the terminal */
- if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &win) == -1)
- fprintf(stderr, "%s: ioctl <stdout> TIOCGWINSZ: %s\n", argv0, strerror(errno));
- else
- cols = win.ws_col;
-
- line = malloc((size_t)cols * 3);
- space = malloc((size_t)cols);
- if (!line || !space) {
- fprintf(stderr, "%s: malloc: %s\n", argv0, strerror(ENOMEM));
- return 1;
- }
- for (i = 0; i < cols; i++) {
- line[i * 3 + 0] = (char)(0xE2);
- line[i * 3 + 1] = (char)(0x94);
- line[i * 3 + 2] = (char)(0x80);
- }
- memset(space, ' ', (size_t)cols);
- space[cols - 1] = '\0';
- line[(cols - 2) * 3] = '\0';
-
- /* stty -icanon -echo */
- if (tcgetattr(STDIN_FILENO, &stty)) {
- fprintf(stderr, "%s: tcgetattr <stdin>: %s\n", argv0, strerror(errno));
- return 1;
- }
- saved_stty = stty;
- stty.c_lflag &= (tcflag_t)~(ICANON | ECHO);
- if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &stty)) {
- fprintf(stderr, "%s: tcsetattr <stdin>: %s\n", argv0, strerror(errno));
- return 1;
- }
-
- /* Hide cursor */
- printf("%s", "\033[?25l");
- fflush(stdout);
-
- /* Fork to diminish risk of unclean exit */
- pid = fork();
- if (pid == (pid_t)-1) {
- fprintf(stderr, "%s: fork: %s\n", argv0, strerror(errno));
- } else if (pid) {
- waitpid(pid, NULL, 0);
+ isinteractive = isatty(STDIN_FILENO);
+ if (isinteractive && init_terminal(&pid, &saved_stty))
goto done;
- }
}
- if (argc) {
- for (; *argv; argv++) {
- if (strchr(*argv, '/'))
- *argv = strrchr(*argv, '/');
- handle_device(*argv, get, !!set, set_value, set_prefix == '+', set_suffix);
- }
+ if (get || set || isinteractive) {
+ update(argc, argv, all, get, set, set_prefix, set_value, set_suffix);
} else {
- if ((dir = opendir(BACKLIGHT_DIR))) {
- while ((ent = readdir(dir))) {
- if (all || strstr(ent->d_name, "acpi_video") == ent->d_name) {
- if (*ent->d_name && *ent->d_name != '.') {
- handle_device(ent->d_name, get, !!set, set_value, set_prefix == '+', set_suffix);
- any = 1;
- }
- }
+ while ((len = getline(&set, &size, stdin)) > 0) {
+ if (len && set[len - 1] == '\n')
+ set[--len] = '\0';
+ if (!len)
+ continue;
+ if (parse_set_argument(set, &set_prefix, &set_value, &set_suffix)) {
+ fprintf(stderr, "%s: invalid input: %s\n", argv0, set);
+ return 0;
}
- closedir(dir);
+ update(argc, argv, all, get, set, set_prefix, set_value, set_suffix);
}
- if (!any)
- fprintf(stderr, "%s: cannot find any backlight devices\n", argv0);
+ if (ferror(stdin)) {
+ fprintf(stderr, "%s: getline <stdin>: %s\n", argv0, strerror(errno));
+ return 1;
+ }
+ free(set);
}
if (get) {
@@ -409,7 +472,7 @@ main(int argc, char *argv[])
}
done:
- if (!get && !set && pid) {
+ if (isinteractive && pid) {
/* Show cursor */
printf("%s", "\033[?25h");
fflush(stdout);
generated by cgit v1.2.3-70-g09d2 (git 2.47.0) at 2024-11-28 20:54:02 +0000