mirror of
https://github.com/python/cpython.git
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134 lines
2.9 KiB
C
134 lines
2.9 KiB
C
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/* Readline interface for tokenizer.c and [raw_]input() in bltinmodule.c.
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By default, or when stdin is not a tty device, we have a super
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simple my_readline function using fgets.
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Optionally, we can use the GNU readline library.
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my_readline() has a different return value from GNU readline():
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- NULL if an interrupt occurred or if an error occurred
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- a malloc'ed empty string if EOF was read
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- a malloc'ed string ending in \n normally
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*/
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#include "Python.h"
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int (*PyOS_InputHook)(void) = NULL;
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#ifdef RISCOS
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int Py_RISCOSWimpFlag;
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#endif
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/* This function restarts a fgets() after an EINTR error occurred
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except if PyOS_InterruptOccurred() returns true. */
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static int
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my_fgets(char *buf, int len, FILE *fp)
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{
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char *p;
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for (;;) {
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if (PyOS_InputHook != NULL)
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(void)(PyOS_InputHook)();
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errno = 0;
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p = fgets(buf, len, fp);
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if (p != NULL)
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return 0; /* No error */
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if (feof(fp)) {
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return -1; /* EOF */
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}
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#ifdef EINTR
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if (errno == EINTR) {
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if (PyOS_InterruptOccurred()) {
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return 1; /* Interrupt */
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}
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continue;
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}
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#endif
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if (PyOS_InterruptOccurred()) {
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return 1; /* Interrupt */
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}
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return -2; /* Error */
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}
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/* NOTREACHED */
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}
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/* Readline implementation using fgets() */
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char *
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PyOS_StdioReadline(char *prompt)
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{
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size_t n;
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char *p;
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n = 100;
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if ((p = PyMem_MALLOC(n)) == NULL)
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return NULL;
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fflush(stdout);
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#ifndef RISCOS
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if (prompt)
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fprintf(stderr, "%s", prompt);
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#else
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if (prompt) {
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if(Py_RISCOSWimpFlag)
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fprintf(stderr, "\x0cr%s\x0c", prompt);
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else
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fprintf(stderr, "%s", prompt);
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}
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#endif
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fflush(stderr);
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switch (my_fgets(p, (int)n, stdin)) {
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case 0: /* Normal case */
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break;
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case 1: /* Interrupt */
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PyMem_FREE(p);
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return NULL;
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case -1: /* EOF */
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case -2: /* Error */
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default: /* Shouldn't happen */
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*p = '\0';
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break;
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}
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#ifdef MPW
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/* Hack for MPW C where the prompt comes right back in the input */
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/* XXX (Actually this would be rather nice on most systems...) */
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n = strlen(prompt);
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if (strncmp(p, prompt, n) == 0)
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memmove(p, p + n, strlen(p) - n + 1);
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#endif
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n = strlen(p);
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while (n > 0 && p[n-1] != '\n') {
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size_t incr = n+2;
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p = PyMem_REALLOC(p, n + incr);
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if (p == NULL)
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return NULL;
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if (incr > INT_MAX) {
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PyErr_SetString(PyExc_OverflowError, "input line too long");
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}
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if (my_fgets(p+n, (int)incr, stdin) != 0)
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break;
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n += strlen(p+n);
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}
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return PyMem_REALLOC(p, n+1);
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}
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/* By initializing this function pointer, systems embedding Python can
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override the readline function.
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Note: Python expects in return a buffer allocated with PyMem_Malloc. */
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char *(*PyOS_ReadlineFunctionPointer)(char *);
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/* Interface used by tokenizer.c and bltinmodule.c */
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char *
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PyOS_Readline(char *prompt)
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{
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char *rv;
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if (PyOS_ReadlineFunctionPointer == NULL) {
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PyOS_ReadlineFunctionPointer = PyOS_StdioReadline;
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}
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Py_BEGIN_ALLOW_THREADS
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rv = (*PyOS_ReadlineFunctionPointer)(prompt);
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Py_END_ALLOW_THREADS
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return rv;
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}
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