FreeCalypso > hg > freecalypso-tools
view loadtools/tpinterf2.c @ 465:003e48f8ebe1
rvinterf/etmsync/fsnew.c: cast 0 to (char *) for execl sentinel
I generally don't use NULL and use plain 0 instead, based on a "NULL
considered harmful" discussion on the classiccmp mailing list many aeons
ago (I couldn't find it, and I reason that it must have been 2005 or
earlier), but a recent complaint by a packager sent me searching, and I
found this:
https://ewontfix.com/11/
While I don't give a @#$% about "modern" systems and code-nazi tools,
I realized that passing a plain 0 as a pointer sentinel in execl is wrong
because it will break on systems where pointers are longer than the plain
int type. Again, I don't give a @#$% about the abomination of x86_64 and
the like, but if anyone ever manages to port my code to something like a
PDP-11 (16-bit int, 32-bit long and pointers), then passing a plain 0
as a function argument where a pointer is expected most definitely won't
work: if the most natural stack slot and SP alignment unit is 16 bits,
fitting an int, with longs and pointers taking up two such slots, then
the call stack will be totally wrong with a plain 0 passed for a pointer.
Casting the 0 to (char *) ought to be the most kosher solution for the
most retro systems possible.
author | Mychaela Falconia <falcon@freecalypso.org> |
---|---|
date | Mon, 11 Feb 2019 00:00:19 +0000 |
parents | e7502631a0f9 |
children | 8d7dcfd9df53 |
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line source
/* * This module provides a more advanced target interface function * than tpinterf.c - programmatic capture of target responses, * for dumps etc. It will be linked by fc-loadtool, but not fc-chainload. */ #include <sys/types.h> #include <sys/time.h> #include <sys/errno.h> #include <stdio.h> #include <string.h> #include <strings.h> #include <stdlib.h> extern int errno; extern int target_fd; /* * This functions reads the serial output from the target until a * '=' prompt is received. All intermediate output is parsed into * lines and passed to a callback function. * * The callback function is called with a pointer to each received * line, stored in a buffer ending in NUL, with CRLF stripped. * The callback function is expected to return an int. If the * callback return value is negative, this function returns immediately * with that negative value. If the callback return value is positive * or zero, it is added to an accumulator. * * Termination: this function returns when it has received a '=' at * the beginning of a line (return value is the callback return * accumulator, or 0 if no lines came), if the callback returns a * negative value (that value is returned), or if an error is detected * within this function (return value -1, and an error message * printed on stderr). */ tpinterf_capture_output(timeout, callback) int timeout; /* seconds */ int (*callback)(); { char buf[512], *cp; char line[1024], *dp = line; fd_set fds; struct timeval tv; int cc, linelen = 0; int totout = 0, cbret; for (;;) { FD_ZERO(&fds); FD_SET(target_fd, &fds); tv.tv_sec = timeout; tv.tv_usec = 0; cc = select(target_fd+1, &fds, NULL, NULL, &tv); if (cc < 0) { if (errno == EINTR) continue; perror("select"); return(-1); } if (cc < 1) { fprintf(stderr, "error: timeout waiting for \'=\' prompt from target\n"); return(-1); } cc = read(target_fd, buf, sizeof buf); if (cc <= 0) { perror("read after successful select"); return(-1); } for (cp = buf; cc; cp++) { cc--; if (*cp == '=' && !linelen && !cc) return(totout); if (*cp == '\r') continue; if (*cp == '\n') { *dp = '\0'; cbret = callback(line); if (cbret < 0) return(cbret); totout += cbret; dp = line; linelen = 0; continue; } *dp++ = *cp; linelen++; if (linelen >= sizeof line) { fprintf(stderr, "error: target response line length exceeds buffer\n"); return(-1); } } } } /* single line response capture mechanism */ /* same line buffer size as in tpinterf_capture_output() */ char target_response_line[1024]; static oneline_catcher(linein) char *linein; { strcpy(target_response_line, linein); return(1); } tpinterf_capture_output_oneline(timeout) { return tpinterf_capture_output(timeout, oneline_catcher); }