Kihaguru Gathura <[email protected]> writes:
> While testing to determine command line arguments passed to a cgi file
> using the *function 1*, I receive the message *output 1.*
> one argument is passed and that is the name of the file.
>
> However, testing with a bogus number 30 for argc in *function 2*, discloses
> multiple arguments beyond the last null argument argv[1] see *output 2.*
> There is also a null value at bogus argc number 29.
>
> Why are these additional argv values generated?
haven't you gone out-of-bound and started printing the envp?
>
>
>
> *Function 1:*
>
>
>
> /**********************************************************************/
>
> void TestCommandLineArguments(int argc, char *argv[])
> {
> unsigned short int i = 0;
>
> if (argc == 1) /* if one command line argument is passed */
> {
> PrintPageUpper();
>
> while(i < argc)
> {
> printf("\t\t<p>(i = %2$d) argc: %1$d, \
> argv[%2$d]: \"%3$s\"</p>\n", argc, \
> i, argv[i]);
> i++;
> }
>
> PrintPageLower();
> exit(EXIT_SUCCESS);
>
> }
>
> if (argc != 1)
> {
> PrintPageUpper();
> puts("\t\t<p>(Multiple Arguments)</p>");
> PrintPageLower();
> exit(EXIT_SUCCESS);
> }
> }
>
>
> /**********************************************************************/
>
>
> *Output 1: *
>
> <p>(i = 0) argc: 1, argv[0]: "//xyz/xyz.html"</p>
>
>
>
>
>
>
> *Function 2:*
>
>
> /**********************************************************************/
>
> void TestCommandLineArguments(int argc, char *argv[])
> {
> unsigned short int i = 0;
> #define BOGUS_ARGC 30
>
> if (argc == 1)
> {
> PrintPageUpper();
>
> while(i < BOGUS_ARGC)
> {
> printf("\t\t<p>(i = %2$d) argc: %1$d, \
> argv[%2$d]: \"%3$s\"</p>\n", BOGUS_ARGC, \
> i, argv[i]);
> i++;
> }
>
> PrintPageLower();
> exit(EXIT_SUCCESS);
>
> }
>
> if (argc == 1)
> {
> PrintPageUpper();
> puts("\t\t<p>(Single Argument)</p>");
> PrintPageLower();
> exit(EXIT_SUCCESS);
> }
> }
>
>
> /**********************************************************************/
>
> *Output 2:*
>
> <p>(i = 0) argc: 30, argv[0]:
> "//xyz/xyz.html"</p>
> <p>(i = 1) argc: 30, argv[1]:
> "(null)"</p>
> <p>(i = 2) argc: 30, argv[2]:
> "SERVER_SOFTWARE=OpenBSD httpd"</p>
> <p>(i = 3) argc: 30, argv[3]:
> "SERVER_PROTOCOL=HTTP/1.1"</p>
> <p>(i = 4) argc: 30, argv[4]:
> "SERVER_NAME=xyz.com"</p>
> <p>(i = 5) argc: 30, argv[5]:
> "SERVER_PORT=443"</p>
> <p>(i = 6) argc: 30, argv[6]:
> "SERVER_ADDR=xyz.xyz.xy.xyz"</p>
> <p>(i = 7) argc: 30, argv[7]:
> "REQUEST_URI=/xyz/xyz.html"</p>
> <p>(i = 8) argc: 30, argv[8]:
> "REQUEST_METHOD=GET"</p>
> <p>(i = 9) argc: 30, argv[9]:
> "REMOTE_PORT=36818"</p>
> <p>(i = 10) argc: 30, argv[10]:
> "REMOTE_ADDR=xyz.xyz.xy.xyz"</p>
> <p>(i = 11) argc: 30, argv[11]:
> "HTTPS=on"</p>
> <p>(i = 12) argc: 30, argv[12]:
> "HTTP_X_FORWARDED_FOR=xyz.xyz.xy.xyz"</p>
> <p>(i = 13) argc: 30, argv[13]:
> "HTTP_X_FORWARDED_BY=xyz.xyz.xy.xyz:8443"</p>
> <p>(i = 14) argc: 30, argv[14]:
> "HTTP_USER_AGENT=Mozilla/5.0 (X11; OpenBSD amd64; rv:62.0)
> Gecko/20100101 Firefox/62.0"</p>
> <p>(i = 15) argc: 30, argv[15]:
> "HTTP_UPGRADE_INSECURE_REQUESTS=1"</p>
> <p>(i = 16) argc: 30, argv[16]:
> "HTTP_HOST=xyz.com"</p>
> <p>(i = 17) argc: 30, argv[17]:
> "HTTP_CONNECTION=keep-alive"</p>
> <p>(i = 18) argc: 30, argv[18]:
> "HTTP_CACHE_CONTROL=max-age=0"</p>
> <p>(i = 19) argc: 30, argv[19]:
> "HTTP_ACCEPT_LANGUAGE=en-US,en;q=0.5"</p>
> <p>(i = 20) argc: 30, argv[20]:
> "HTTP_ACCEPT_ENCODING=gzip, deflate, br"</p>
> <p>(i = 21) argc: 30, argv[21]:
> "HTTP_ACCEPT=text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8"</p>
> <p>(i = 22) argc: 30, argv[22]:
> "GATEWAY_INTERFACE=CGI/1.1"</p>
> <p>(i = 23) argc: 30, argv[23]:
> "DOCUMENT_URI=/xyz/xyz.html"</p>
> <p>(i = 24) argc: 30, argv[24]:
> "DOCUMENT_ROOT=/"</p>
> <p>(i = 25) argc: 30, argv[25]:
> "QUERY_STRING="</p>
> <p>(i = 26) argc: 30, argv[26]:
> "SCRIPT_FILENAME=//xyz/xyz.html"</p>
> <p>(i = 27) argc: 30, argv[27]:
> "SCRIPT_NAME=/xyz/xyz.html"</p>
> <p>(i = 28) argc: 30, argv[28]:
> "PATH_INFO="</p>
> <p>(i = 29) argc: 30, argv[29]:
> "(null)"</p>
>
> Please note: the actual ip addresses and file names are hereby masked
