linux - How can I verify in my C program that four terminals are currently open? -

-

so i'm going preface saying homework project in class. supposed determine user opened 4 terminal windows before running program, , have determining if can open 4 terminal number buffers /dev/pts/ read-only. have save these first 4 buffers can open them again write terminals. know how open files fopen issue terminals aren't open anymore still show , accessible. know pretty frowned upon ask homework i've been working @ hours , don't want written me want direction. how can check there 4 terminals open using method have use? here's code maybe 1 of y'all can see i'm doing wrong.

#include <stdio.h> #include <stdlib.h>  #define maxline 100  int main(){     int i, ptsnum[4], ptscount = 0;     file *fp;     char ptsname[20];      for(i = 0; < 20; i++){         // append terminal number end of buffer name         sprintf(ptsname, "/dev/pts/%d", i);         // try open file         if((fp = fopen(ptsname, "r")) != null){             // save terminal number if buffer exists             ptsnum[ptscount] = i;             ptscount++;             fclose(fp);         }     }  return 0; }

well, try open terminals, once them counted, fclose(3) them, in case want them open, don't last fclose(3) @ end of loop.


Comments

Post a Comment

Popular posts from this blog

Django REST Framework perform_create: You cannot call `.save()` after accessing `serializer.data` -

-
i have following viewset: class artistprofileviewset(viewsets.modelviewset): queryset = artistprofile.objects.all() serializer_class = artistprofileserializer def perform_create(self, serializer): if serializer.is_valid(): serializer.save() with following serializers: class simpleartisttrackserializer(serializers.hyperlinkedmodelserializer): class meta: model = artisttrack fields = (...my fields...) class artistprofileserializer(serializers.hyperlinkedmodelserializer): owners = userserializer(many=true, required=false) tracks = simpleartisttrackserializer(many=true, required=false) class meta: model = artistprofile fields = (...my fields...) i getting following error: assertionerror: cannot call `.save()` after accessing `serializer.data`.if need access data before committing database inspect 'serializer.validated_data' instead. i don't see editing serializer.data object. th...
Read more

Why does Go error when trying to marshal this JSON? -

-
i'm trying rather simple example of trying decode json file structs using golang. however, when attempting error that json: cannot unmarshal object go value of type []main.track which don't understand. here's code in question, , json can found here . package main import ( "encoding/json" "fmt" "net/http" "os" ) // tracks group of track types type tracks struct { tracks []track } // track represents singular track type track struct { name string url string artist artist } // artist represents single artist type artist struct { name string mbid string url string } func main() { url := "http://ws.audioscrobbler.com/2.0/?method=geo.gettoptracks&api_key=c1572082105bd40d247836b5c1819623&format=json&country=netherlands" response, err := http.get(url) if err != nil { fmt.printf("%s\n", err) os.exit(1) } de...
Read more