Data commit

Task/Get-system-command-output/C/get-system-command-output.c

@@ -0,0 +1,36 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+int main(int argc, char **argv)
+{
+    if (argc < 2) return 1;
+
+    FILE *fd;
+    fd = popen(argv[1], "r");
+    if (!fd) return 1;
+
+    char   buffer[256];
+    size_t chread;
+    /* String to store entire command contents in */
+    size_t comalloc = 256;
+    size_t comlen   = 0;
+    char  *comout   = malloc(comalloc);
+
+    /* Use fread so binary data is dealt with correctly */
+    while ((chread = fread(buffer, 1, sizeof(buffer), fd)) != 0) {
+        if (comlen + chread >= comalloc) {
+            comalloc *= 2;
+            comout = realloc(comout, comalloc);
+        }
+        memmove(comout + comlen, buffer, chread);
+        comlen += chread;
+    }
+
+    /* We can now work with the output as we please. Just print
+     * out to confirm output is as expected */
+    fwrite(comout, 1, comlen, stdout);
+    free(comout);
+    pclose(fd);
+    return 0;
+}