/* execute a system call and return stream from STDOUT */
void
f_system(union argument *arg)
{
struct value val, result;
struct udvt_entry *errno_var;
char *output;
int output_len, ierr;
/* Retrieve parameters from top of stack */
pop(&val);
/* Make sure parameters are of the correct type */
if (val.type != STRING)
int_error(NO_CARET, "non-string argument to system()");
FPRINTF((stderr," f_system input = \"%s\"\n", val.v.string_val));
ierr = do_system_func(val.v.string_val, &output);
if ((errno_var = add_udv_by_name("ERRNO"))) {
errno_var->udv_undef = FALSE;
Ginteger(&errno_var->udv_value, ierr);
}
output_len = strlen(output);
/* chomp result */
if ( output_len > 0 && output[output_len-1] == '\n' )
output[output_len-1] = NUL;
FPRINTF((stderr," f_system result = \"%s\"\n", output));
push(Gstring(&result, output));
gpfree_string(&result); /* free output */
gpfree_string(&val); /* free command string */
}
/* substitute output from ` `
* *strp points to the input string. (*strp)[current] is expected to
* be the initial back tic. Characters through the following back tic
* are replaced by the output of the command. extend_input_line()
* is called to extend *strp array if needed.
*/
static void
substitute(char **strp, size_t *str_lenp, int current)
{
char *last;
char c;
char *str, *pgm, *rest = NULL;
char *output;
size_t pgm_len, rest_len = 0;
int output_pos;
/* forgive missing closing backquote at end of line */
str = *strp + current;
last = str;
while (*++last) {
if (*last == '`')
break;
}
pgm_len = last - str;
pgm = gp_alloc(pgm_len, "command string");
safe_strncpy(pgm, str + 1, pgm_len); /* omit ` to leave room for NUL */
/* save rest of line, if any */
if (*last) {
last++; /* advance past ` */
rest_len = strlen(last) + 1;
if (rest_len > 1) {
rest = gp_alloc(rest_len, "input line copy");
strcpy(rest, last);
}
}
/* do system call */
(void) do_system_func(pgm, &output);
free(pgm);
/* now replace ` ` with output */
output_pos = 0;
while ((c = output[output_pos++])) {
if (c != '\n' && c != '\r')
(*strp)[current++] = c;
if (current == *str_lenp)
extend_input_line();
}
(*strp)[current] = 0;
free(output);
/* tack on rest of line to output */
if (rest) {
while (current + rest_len > *str_lenp)
extend_input_line();
strcpy(*strp + current, rest);
free(rest);
}
screen_ok = FALSE;
}