FreeCalypso > hg > freecalypso-tools
view rvinterf/tmsh/usercmd.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 | 0f2db8baf8db |
children | 4c7f3778dc24 |
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/* * This module implements fc-tmsh user command dispatch. */ #include <sys/types.h> #include <ctype.h> #include <stdio.h> #include <string.h> #include <strings.h> #include <stdlib.h> #include "exitcodes.h" extern char usercmd[]; extern int cmd_abbr(); extern int cmd_abbw(); extern int cmd_aul(); extern int cmd_aur(); extern int cmd_aus(); extern int cmd_auw(); extern int cmd_auw_fir(); extern int cmd_check_ffs1(); extern int cmd_dieid(); extern int cmd_ffs2(); extern int cmd_me(); extern int cmd_mpr(); extern int cmd_mpw(); extern int cmd_oabbr(); extern int cmd_oabbw(); extern int cmd_omr(); extern int cmd_omw(); extern int cmd_ping(); extern int cmd_r8(); extern int cmd_r16(); extern int cmd_r32(); extern int cmd_rfe(); extern int cmd_rfpr(); extern int cmd_rfpw(); extern int cmd_rftr(); extern int cmd_rftw(); extern int cmd_rxpr(); extern int cmd_rxpw(); extern int cmd_save_rf_table(); extern int cmd_save_rf_table_raw(); extern int cmd_save_tx_ramp(); extern int cmd_scr(); extern int cmd_scw(); extern int cmd_sr(); extern int cmd_tgtreset(); extern int cmd_tm3ver(); extern int cmd_tminit(); extern int cmd_tmpkt(); extern int cmd_tms(); extern int cmd_ttr(); extern int cmd_ttw(); extern int cmd_txpr(); extern int cmd_txpw(); extern int cmd_version(); extern int cmd_w8(); extern int cmd_w16(); extern int cmd_w32(); cmd_exit() { tty_cleanup(); exit(0); } static struct cmdtab { char *cmd; int minargs; int maxargs; int (*func)(); } cmdtab[] = { {"abbr", 2, 2, cmd_abbr}, {"abbw", 3, 3, cmd_abbw}, {"aul", 1, 1, cmd_aul}, {"aur", 1, 1, cmd_aur}, {"aus", 1, 1, cmd_aus}, {"auw", 2, 126, cmd_auw}, {"auw-fir", 2, 2, cmd_auw_fir}, {"check-ffs1", 0, 0, cmd_check_ffs1}, {"dieid", 0, 0, cmd_dieid}, {"etmpkt", 1, 253, cmd_tmpkt}, {"exit", 0, 0, cmd_exit}, {"ffs2", 1, 3, cmd_ffs2}, {"me", 1, 1, cmd_me}, {"mpr", 1, 1, cmd_mpr}, {"mpw", 2, 2, cmd_mpw}, {"oabbr", 2, 2, cmd_oabbr}, {"oabbw", 3, 3, cmd_oabbw}, {"omr", 2, 2, cmd_omr}, {"omw", 2, 129, cmd_omw}, {"ping", 0, 2, cmd_ping}, {"quit", 0, 0, cmd_exit}, {"r8", 1, 2, cmd_r8}, {"r16", 1, 2, cmd_r16}, {"r32", 1, 2, cmd_r32}, {"rfe", 1, 1, cmd_rfe}, {"rfpr", 1, 1, cmd_rfpr}, {"rfpw", 2, 3, cmd_rfpw}, {"rftr", 1, 1, cmd_rftr}, {"rftw", 2, 3, cmd_rftw}, {"rxpr", 1, 1, cmd_rxpr}, {"rxpw", 2, 2, cmd_rxpw}, {"save-rf-table", 1, 1, cmd_save_rf_table}, {"save-rf-table-raw", 1, 1, cmd_save_rf_table_raw}, {"save-tx-ramp", 1, 1, cmd_save_tx_ramp}, {"scr", 1, 1, cmd_scr}, {"scw", 2, 2, cmd_scw}, {"sr", 2, 2, cmd_sr}, {"tgtreset", 0, 0, cmd_tgtreset}, {"tm3ver", 1, 1, cmd_tm3ver}, {"tminit", 0, 0, cmd_tminit}, {"tmpkt", 1, 253, cmd_tmpkt}, {"tms", 1, 1, cmd_tms}, {"ttr", 1, 1, cmd_ttr}, {"ttw", 2, 2, cmd_ttw}, {"txpr", 1, 1, cmd_txpr}, {"txpw", 2, 2, cmd_txpw}, {"version", 1, 1, cmd_version}, {"w8", 2, 246, cmd_w8}, {"w16", 2, 123, cmd_w16}, {"w32", 2, 62, cmd_w32}, {0, 0, 0, 0} }; void dispatch_user_cmd() { char *argv[257]; char *cp, **ap; struct cmdtab *tp; for (cp = usercmd; isspace(*cp); cp++) ; if (!*cp || *cp == '#') return; argv[0] = cp; while (*cp && !isspace(*cp)) cp++; if (*cp) *cp++ = '\0'; for (tp = cmdtab; tp->cmd; tp++) if (!strcmp(tp->cmd, argv[0])) break; if (!tp->func) { printf("error: no such command\n"); return; } for (ap = argv + 1; ; ) { while (isspace(*cp)) cp++; if (!*cp || *cp == '#') break; if (ap - argv - 1 >= tp->maxargs) { printf("error: too many arguments\n"); return; } if (*cp == '"') { *ap++ = ++cp; while (*cp && *cp != '"') cp++; if (*cp != '"') { printf("error: unterminated quoted string\n"); return; } *cp++ = '\0'; } else { *ap++ = cp; while (*cp && !isspace(*cp)) cp++; if (*cp) *cp++ = '\0'; } } if (ap - argv - 1 < tp->minargs) { printf("error: too few arguments\n"); return; } *ap = 0; tp->func(ap - argv, argv); } dispatch_oneshot_cmd(argc, argv) char **argv; { struct cmdtab *tp; for (tp = cmdtab; tp->cmd; tp++) if (!strcmp(tp->cmd, argv[0])) break; if (!tp->func) { fprintf(stderr, "error: \"%s\" is not a valid command\n", argv[0]); exit(ERROR_USAGE); } if (argc - 1 > tp->maxargs) { fprintf(stderr, "%s: too many arguments\n", tp->cmd); exit(ERROR_USAGE); } if (argc - 1 < tp->minargs) { fprintf(stderr, "%s: too few arguments\n", tp->cmd); exit(ERROR_USAGE); } return tp->func(argc, argv); }