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POexecl doesn't work in a while(1) loop, server side; C script
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  1. POexecl doesn't work in a while(1) loop, server side; C script
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    copied!<p>I have a problem with a little C script which should run as a server and launch a popup for every message arriving. The <a href="http://linux.about.com/library/cmd/blcmdl3_execl.htm" rel="nofollow noreferrer">execl</a> syntax is correct because if I try a little script with </p> <pre><code>main() { execl(...); } </code></pre> <p>it works.</p> <p>When I put it in a while(1) loop it doesn't work. Everything else is working, like <code>printf</code> or string operation, but not the <code>execl</code>. Even if I fork it doesn't work. How can I make it work?</p> <p>And I've tried with the <code>fork()</code>, but it doesn't work either.</p> <p>Here's the complete server C code.</p> <pre><code>#include &lt;arpa/inet.h&gt; #include &lt;netinet/in.h&gt; #include &lt;stdio.h&gt; #include &lt;stdlib.h&gt; #include &lt;sys/types.h&gt; #include &lt;sys/socket.h&gt; #include &lt;unistd.h&gt; #include &lt;string.h&gt; #define BUFLEN 512 #define PORT 9930 void diep(char *s) { perror(s); exit(1); } int main() { struct sockaddr_in si_me, si_other; int s, i, slen=sizeof(si_other), broadcastPermission; char buf[100], zeni[BUFLEN]; if ((s=socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP))==-1) diep("socket"); broadcastPermission = 1; if (setsockopt(s, SOL_SOCKET, SO_BROADCAST, (void *) &amp;broadcastPermission, sizeof(broadcastPermission)) &lt; 0) diep("setsockopt() failed"); memset((char *) &amp;si_me, 0, sizeof(si_me)); si_me.sin_family = AF_INET; si_me.sin_port = htons(PORT); si_me.sin_addr.s_addr = htonl(INADDR_ANY); if (bind(s, &amp;si_me, sizeof(si_me))==-1) diep("bind"); while (1) { if (recvfrom(s, buf, BUFLEN, 0, &amp;si_other, &amp;slen)==-1) diep("recvfrom()"); //printf("Received packet from %s:%d\nData: %s\n", inet_ntoa(si_other.sin_addr), ntohs(si_other.sin_port), buf); strcpy(zeni, ""); strcat(zeni, "zenity --warning --title Hack!! --text "); strcat(zeni, buf); printf("cmd: %s\n", zeni); //system (zeni); execl("/usr/bin/zenity", "/usr/bin/zenity", "--warning", "--title", "Warn!", "--text", buf, (char *) NULL); } close(s); return 0; } </code></pre>
 

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