Data commit

Task/Execute-a-system-command/Amazing-Hopper/execute-a-system-command.hopper

@@ -0,0 +1,26 @@
+#!/usr/bin/hopper
+
+#include <hopper.h>
+
+main:
+
+  /* execute "ls -lstar" with no result return (only displayed) */
+  {"ls -lstar"},execv
+
+  /* this form does not allow composition of the line with variables.
+     Save result in the variable "s", and then display it */
+  s=`ls -l | awk '{if($2=="2")print $0;}'`
+  {"\n",s,"\n"}print
+
+  data="2"
+  {""}tok sep
+
+  // the same as above, only I can compose the line:
+  {"ls -l | awk '{if($2==\"",data,"\")print $0;}'"}join(s),{s}exec,print
+  {"\n\n"}print
+
+  // this does the same as above, with an "execute" macro inside a "let" macro:
+  t=0,let (t := execute( {"ls -l | awk '{if($2==\""},{data},{"\")print $0;}'"} ))
+  {t,"\n"}print
+
+{0}return