--- /dev/null
+int main(int argc, char *argv[], char *envp[])
+{
+ FILE *pipe[4];
+ FILE *pipein;
+ char *cmd_string[4]={
+ "pnmtopng",
+ "pnmmargin -white 10",
+ "pnmcrop",
+ "gs -sDEVICE=ppmraw -sOutputFile=- -sNOPAUSE -q - -c showpage -c quit"
+ };
+ char content[]="Content-type: image/png\n\n";
+ int i;
+ /* write mime-type to stdout */
+ write(STDOUT_FILENO, content, strlen(content));
+ /* execute chain of command */
+ for (i=0; i<4; i++) {
+ pipe[i] = popen(cmd_string[i], "w");
+ dup2(fileno(pipe[i]), STDOUT_FILENO);
+ }
+ /* create barcode (in PS) */
+ pipein = popen("barcode", "w");
+ /* send barcode string to barcode program */
+ write(fileno(pipein), argv[1], strlen(argv[1]));
+ /* close all pipes (in reverse order) */
+ for (i=4; i==0; i--) {
+ pclose((pipe[i]));
+ }
+ exit(0);
+}