diff options
| -rw-r--r-- | i3status.c | 13 | ||||
| -rw-r--r-- | include/i3status.h | 3 | ||||
| -rw-r--r-- | src/auto_detect_format.c | 142 |
3 files changed, 157 insertions, 1 deletions
@@ -173,7 +173,7 @@ int main(int argc, char *argv[]) { unsigned int j; cfg_opt_t general_opts[] = { - CFG_STR("output_format", "dzen2", CFGF_NONE), + CFG_STR("output_format", "auto", CFGF_NONE), CFG_BOOL("colors", 1, CFGF_NONE), CFG_STR("color_good", "#00FF00", CFGF_NONE), CFG_STR("color_degraded", "#FFFF00", CFGF_NONE), @@ -312,6 +312,17 @@ int main(int argc, char *argv[]) { die("Could not get section \"general\"\n"); char *output_str = cfg_getstr(cfg_general, "output_format"); + if (strcasecmp(output_str, "auto") == 0) { + fprintf(stderr, "i3status: trying to auto-detect output_format setting\n"); + output_str = auto_detect_format(); + if (!output_str) { + output_str = "none"; + fprintf(stderr, "i3status: falling back to \"none\"\n"); + } else { + fprintf(stderr, "i3status: auto-detected \"%s\"\n", output_str); + } + } + if (strcasecmp(output_str, "dzen2") == 0) output_format = O_DZEN2; else if (strcasecmp(output_str, "xmobar") == 0) diff --git a/include/i3status.h b/include/i3status.h index ae1983c..125ca55 100644 --- a/include/i3status.h +++ b/include/i3status.h @@ -59,6 +59,9 @@ void print_seperator(); char *color(const char *colorstr); char *endcolor() __attribute__ ((pure)); +/* src/auto_detect_format.c */ +char *auto_detect_format(); + void print_ipv6_info(const char *format_up, const char *format_down); void print_disk_info(const char *path, const char *format); void print_battery_info(int number, const char *format, bool last_full_capacity); diff --git a/src/auto_detect_format.c b/src/auto_detect_format.c new file mode 100644 index 0000000..b8dfdfc --- /dev/null +++ b/src/auto_detect_format.c @@ -0,0 +1,142 @@ +/* + * vim:ts=4:sw=4:expandtab + */ +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> +#include <stdbool.h> +#include <stdint.h> +#include <sys/types.h> +#include <sys/stat.h> +#include <fcntl.h> +#include <dirent.h> + +#include "i3status.h" + +/* + * This function tries to automatically find out where i3status is being piped + * to and choses the appropriate output format. + * + * It is a little hackish but should work for most setups :). + * + * By iterating through /proc/<number>/stat and finding out the parent process + * id (just like pstree(1) or ps(1) work), we can get all children of our + * parent. When the output of i3status is being piped somewhere, the shell + * (parent process) spawns i3status and the destination process, so we will + * find our own process and the pipe target. + * + * We then check whether the pipe target’s name is known and chose the format. + * + */ +char *auto_detect_format() { + pid_t myppid = getppid(); + pid_t mypid = getpid(); + + DIR *dir; + struct dirent *entry; + char path[255]; + /* the relevant contents (for us) are: + * <pid> (<program name>) <status> <ppid> + * which should well fit into one page of 4096 bytes */ + char buffer[4096]; + + char *format = NULL; + + char *parentname = NULL; + + if (!(dir = opendir("/proc"))) + return NULL; + + /* First pass: get the executable name of the parent. + * Upon error, we directly return NULL as we cannot continue without the + * name of our parent process. */ + while ((entry = readdir(dir)) != NULL) { + pid_t pid = (pid_t)atoi(entry->d_name); + if (pid != myppid) + continue; + + if (snprintf(path, sizeof(path), "/proc/%d/stat", pid) == -1 || + !slurp(path, buffer, 4095)) + goto out; + + buffer[4095] = '\0'; + char *leftbracket = strchr(buffer, '('); + char *rightbracket = strrchr(buffer, ')'); + if (!leftbracket || + !rightbracket || + !(parentname = malloc((rightbracket - leftbracket)))) + goto out; + *rightbracket = '\0'; + strcpy(parentname, leftbracket + 1); + } + + if (!parentname) + goto out; + + rewinddir(dir); + + while ((entry = readdir(dir)) != NULL) { + pid_t pid = (pid_t)atoi(entry->d_name); + if (pid == 0 || pid == mypid) + continue; + + if (snprintf(path, sizeof(path), "/proc/%d/stat", pid) == -1) + continue; + + char *name = NULL; + pid_t ppid; + int loopcnt = 0; + /* Now we need to find out the name of the process. + * To avoid the possible race condition of the process existing already + * but not executing the destination (shell after fork() and before + * exec()), we check if the name equals its parent. + * + * We try this for up to 0.5 seconds, then we give up. + */ + do { + /* give the scheduler a chance between each iteration, don’t hog + * the CPU too much */ + if (name) + usleep(50); + + if (!slurp(path, buffer, 4095)) + break; + buffer[4095] = '\0'; + char *leftbracket = strchr(buffer, '('); + char *rightbracket = strrchr(buffer, ')'); + if (!leftbracket || + !rightbracket || + sscanf(rightbracket + 2, "%*c %d", &ppid) != 1 || + ppid != myppid) + break; + *rightbracket = '\0'; + name = leftbracket + 1; + } while (strcmp(parentname, name) == 0 && loopcnt++ < 10000); + + if (!name) + continue; + + /* Check for known destination programs and set format */ + char *newfmt = NULL; + if (strcasecmp(name, "i3bar") == 0) + newfmt = "none"; + else if (strcasecmp(name, "dzen2") == 0) + newfmt = "dzen2"; + else if (strcasecmp(name, "xmobar") == 0) + newfmt = "xmobar"; + + if (newfmt && format) { + fprintf(stderr, "i3status: cannot auto-configure, situation ambiguous (format \"%s\" *and* \"%s\" detected)\n", newfmt, format); + format = NULL; + break; + } else { + format = newfmt; + } + } + +out: + closedir(dir); + + return format; +} |