SwapView

swapview.d

#!/usr/bin/dmd -run

import std.stdio, std.file, std.path, std.string, std.conv, std.math;

struct SwapMap {
    string pid;
    double size = 0;
    string cmd;
}

SwapMap[] mapsort(SwapMap[] swapmap){
    if(swapmap.length <= 1)
        return swapmap;
    SwapMap[] lmap;
    SwapMap[] rmap;
    foreach(SwapMap swaps; swapmap[1 .. swapmap.length]){
        if(swaps.size < swapmap[0].size){
            lmap ~= swaps;
        }else{
            rmap ~= swaps;
        }
    }
    return mapsort(lmap)~swapmap[0 .. 1]~mapsort(rmap);
}

string filesize(double size){
    string units = "KMGT";
    double left = size.abs();
    int unit = -1;

    while(left > 1100 && unit < 3){
        left /=1024;
        unit += 1;
    }
    if(unit == -1){
        return format("%dB", to!int(size));
    }else{
        if(size < 0)
            left = -left;
        return format("%.1%siB", left, units[unit]);
    }
}

SwapMap getswapfor(string pid){
    SwapMap swaps;
    try{
        File file = File("/proc/"~pid~"/smaps", "r");
        foreach(string line; lines(file)){
            line = chomp(line);
/*
        // 据说性能比较好？
        char[] buf;
        while (!file.eof()){
            file.readln(buf);
            string line = chomp(to!string(buf));
*/
            if(!line.indexOf("Swap:")){
                swaps.size += to!int(line.split()[1]);
            }
        }
        file.close();
        if(!swaps.size)
            return swaps;
        swaps.pid = pid;
        swaps.size = swaps.size*1024;
        swaps.text = chomp(readText("/proc/"~pid~"/cmdline"));
    }catch(StdioException e){
        writeln(e.msg);
        return swaps;
    }
    return swaps;
}

SwapMap[] getswaps(){
    SwapMap[] swaps;
    SwapMap tmps;
    string pid;
    foreach(DirEntry dirs; dirEntries("/proc", SpanMode.shallow)){
        pid = baseName(dirs.name);
        if(pid.isNumeric()){
            tmps = getswapfor(pid);
            if(tmps.size)
                swaps ~= tmps;
        }
    }

    return swaps;
}

void main(){
    string m = "%5s %9s %s";
    int total = 0;
    writeln(format(m , "PID", "SWAP", "COMMAND"));
    SwapMap[] swapmap = mapsort(getswaps());
    foreach(SwapMap swaps; swapmap){
        total += swaps.size;
        writeln(format(m, swaps.pid, filesize(swaps.size), swaps.cmd));
    }
    writeln("Total: ", filesize(total));
}