mirror of https://github.com/python/cpython.git
122 lines
2.7 KiB
C
122 lines
2.7 KiB
C
|
|
/* Readline interface for tokenizer.c and [raw_]input() in bltinmodule.c.
|
|
By default, or when stdin is not a tty device, we have a super
|
|
simple my_readline function using fgets.
|
|
Optionally, we can use the GNU readline library.
|
|
my_readline() has a different return value from GNU readline():
|
|
- NULL if an interrupt occurred or if an error occurred
|
|
- a malloc'ed empty string if EOF was read
|
|
- a malloc'ed string ending in \n normally
|
|
*/
|
|
|
|
#include "Python.h"
|
|
|
|
int (*PyOS_InputHook)(void) = NULL;
|
|
|
|
/* This function restarts a fgets() after an EINTR error occurred
|
|
except if PyOS_InterruptOccurred() returns true. */
|
|
|
|
static int
|
|
my_fgets(char *buf, int len, FILE *fp)
|
|
{
|
|
char *p;
|
|
for (;;) {
|
|
if (PyOS_InputHook != NULL)
|
|
(void)(PyOS_InputHook)();
|
|
errno = 0;
|
|
p = fgets(buf, len, fp);
|
|
if (p != NULL)
|
|
return 0; /* No error */
|
|
if (feof(fp)) {
|
|
return -1; /* EOF */
|
|
}
|
|
#ifdef EINTR
|
|
if (errno == EINTR) {
|
|
if (PyOS_InterruptOccurred()) {
|
|
return 1; /* Interrupt */
|
|
}
|
|
continue;
|
|
}
|
|
#endif
|
|
if (PyOS_InterruptOccurred()) {
|
|
return 1; /* Interrupt */
|
|
}
|
|
return -2; /* Error */
|
|
}
|
|
/* NOTREACHED */
|
|
}
|
|
|
|
|
|
/* Readline implementation using fgets() */
|
|
|
|
char *
|
|
PyOS_StdioReadline(char *prompt)
|
|
{
|
|
size_t n;
|
|
char *p;
|
|
n = 100;
|
|
if ((p = PyMem_MALLOC(n)) == NULL)
|
|
return NULL;
|
|
fflush(stdout);
|
|
if (prompt)
|
|
fprintf(stderr, "%s", prompt);
|
|
fflush(stderr);
|
|
switch (my_fgets(p, (int)n, stdin)) {
|
|
case 0: /* Normal case */
|
|
break;
|
|
case 1: /* Interrupt */
|
|
PyMem_FREE(p);
|
|
return NULL;
|
|
case -1: /* EOF */
|
|
case -2: /* Error */
|
|
default: /* Shouldn't happen */
|
|
*p = '\0';
|
|
break;
|
|
}
|
|
#ifdef MPW
|
|
/* Hack for MPW C where the prompt comes right back in the input */
|
|
/* XXX (Actually this would be rather nice on most systems...) */
|
|
n = strlen(prompt);
|
|
if (strncmp(p, prompt, n) == 0)
|
|
memmove(p, p + n, strlen(p) - n + 1);
|
|
#endif
|
|
n = strlen(p);
|
|
while (n > 0 && p[n-1] != '\n') {
|
|
size_t incr = n+2;
|
|
p = PyMem_REALLOC(p, n + incr);
|
|
if (p == NULL)
|
|
return NULL;
|
|
if (incr > INT_MAX) {
|
|
PyErr_SetString(PyExc_OverflowError, "input line too long");
|
|
}
|
|
if (my_fgets(p+n, (int)incr, stdin) != 0)
|
|
break;
|
|
n += strlen(p+n);
|
|
}
|
|
return PyMem_REALLOC(p, n+1);
|
|
}
|
|
|
|
|
|
/* By initializing this function pointer, systems embedding Python can
|
|
override the readline function.
|
|
|
|
Note: Python expects in return a buffer allocated with PyMem_Malloc. */
|
|
|
|
char *(*PyOS_ReadlineFunctionPointer)(char *);
|
|
|
|
|
|
/* Interface used by tokenizer.c and bltinmodule.c */
|
|
|
|
char *
|
|
PyOS_Readline(char *prompt)
|
|
{
|
|
char *rv;
|
|
if (PyOS_ReadlineFunctionPointer == NULL) {
|
|
PyOS_ReadlineFunctionPointer = PyOS_StdioReadline;
|
|
}
|
|
Py_BEGIN_ALLOW_THREADS
|
|
rv = (*PyOS_ReadlineFunctionPointer)(prompt);
|
|
Py_END_ALLOW_THREADS
|
|
return rv;
|
|
}
|