dwmblocks.c (DWM)

#include<stdlib.h>
#include<stdio.h>
#include<string.h>
#include<unistd.h>
#include<signal.h>
#include<X11/Xlib.h>
#define LENGTH(X)               (sizeof(X) / sizeof (X[0]))
#define CMDLENGTH       50

typedef struct {
    char* icon;
    char* command;
    unsigned int interval;
    unsigned int signal;
} Block;
void sighandler(int num);
void buttonhandler(int sig, siginfo_t *si, void *ucontext);
void getcmds(int time);
#ifndef __OpenBSD__
void getsigcmds(int signal);
void setupsignals();
void sighandler(int signum);
#endif
int getstatus(char *str, char *last);
void setroot();
void statusloop();
void termhandler(int signum);


#include "blocks.h"

static Display *dpy;
static int screen;
static Window root;
static char statusbar[LENGTH(blocks)][CMDLENGTH] = {0};
static char statusstr[2][256];
static char button[] = "\0";
static int statusContinue = 1;
static void (*writestatus) () = setroot;

//opens process *cmd and stores output in *output
void getcmd(const Block *block, char *output)
{
    if (block->signal)
    {
        output[0] = block->signal;
        output++;
    }
    strcpy(output, block->icon);
    char *cmd = block->command;
    FILE *cmdf;
    if (*button)
    {
        setenv("BUTTON", button, 1);
        cmdf = popen(cmd,"r");
        *button = '\0';
        unsetenv("BUTTON");
    }
    else
    {
        cmdf = popen(cmd,"r");
    }
    if (!cmdf)
        return;
    char c;
    int i = strlen(block->icon);
    fgets(output+i, CMDLENGTH-i, cmdf);
    i = strlen(output);
    if (delim != '\0' && --i)
        output[i++] = delim;
    output[i++] = '\0';
    pclose(cmdf);
}

void getcmds(int time)
{
    const Block* current;
    for(int i = 0; i < LENGTH(blocks); i++)
    {
        current = blocks + i;
        if ((current->interval != 0 && time % current->interval == 0) || time == -1)
            getcmd(current,statusbar[i]);
    }
}

#ifndef __OpenBSD__
void getsigcmds(int signal)
{
    const Block *current;
    for (int i = 0; i < LENGTH(blocks); i++)
    {
        current = blocks + i;
        if (current->signal == signal)
            getcmd(current,statusbar[i]);
    }
}

void setupsignals()
{
    struct sigaction sa;
    for(int i = 0; i < LENGTH(blocks); i++)
    {
        if (blocks[i].signal > 0)
        {
            signal(SIGRTMIN+blocks[i].signal, sighandler);
            sigaddset(&sa.sa_mask, SIGRTMIN+blocks[i].signal); // ignore signal when handling SIGUSR1
        }
    }
    sa.sa_sigaction = buttonhandler;
    sa.sa_flags = SA_SIGINFO;
    sigaction(SIGUSR1, &sa, NULL);
}
#endif

int getstatus(char *str, char *last)
{
    strcpy(last, str);
    str[0] = '\0';
    for(int i = 0; i < LENGTH(blocks); i++)
        strcat(str, statusbar[i]);
    str[strlen(str)-1] = '\0';
    return strcmp(str, last);//0 if they are the same
}

void setroot()
{
    if (!getstatus(statusstr[0], statusstr[1]))//Only set root if text has changed.
        return;
    Display *d = XOpenDisplay(NULL);
    if (d) {
        dpy = d;
    }
    screen = DefaultScreen(dpy);
    root = RootWindow(dpy, screen);
    XStoreName(dpy, root, statusstr[0]);
    XCloseDisplay(dpy);
}

void pstdout()
{
    if (!getstatus(statusstr[0], statusstr[1]))//Only write out if text has changed.
        return;
    printf("%s\n",statusstr[0]);
    fflush(stdout);
}


void statusloop()
{
#ifndef __OpenBSD__
    setupsignals();
#endif
    int i = 0;
    getcmds(-1);
    while(statusContinue)
    {
        getcmds(i);
        writestatus();
        sleep(1.0);
        i++;
    }
}

#ifndef __OpenBSD__
void sighandler(int signum)
{
    getsigcmds(signum-SIGRTMIN);
    writestatus();
}

void buttonhandler(int sig, siginfo_t *si, void *ucontext)
{
    *button = '0' + si->si_value.sival_int & 0xff;
    getsigcmds(si->si_value.sival_int >> 8);
    writestatus();
}
#endif

void termhandler(int signum)
{
    statusContinue = 0;
    exit(0);
}

int main(int argc, char** argv)
{
    for(int i = 0; i < argc; i++)
    {
        if (!strcmp("-d",argv[i]))
            delim = argv[++i][0];
        else if(!strcmp("-p",argv[i]))
            writestatus = pstdout;
    }
    signal(SIGTERM, termhandler);
    signal(SIGINT, termhandler);
    statusloop();
}