FreeCalypso > hg > freecalypso-tools
view uptools/atcmd/smwrite.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 | ce3b57b8920b |
children | dc2fd8e6f42c |
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/* * This program is a debug and development aid - it uses the AT+CMGW command * in PDU mode to write messages into SIM or ME SMS storage, simulating * arbitrary received or sent messages. This trick may come in useful * in the development and testing of SMS handling in phone handset UI firmware. */ #include <sys/types.h> #include <ctype.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <strings.h> #include <unistd.h> #include "../../rvinterf/include/exitcodes.h" extern char at_response[]; char input_line[176*2+2]; int lineno; process_cmdline(argc, argv) char **argv; { int c; extern int optind; while ((c = getopt(argc, argv, "B:np:RX:")) != EOF) if (!atinterf_cmdline_opt(c)) { /* error msg already printed */ exit(ERROR_USAGE); } if (argc != optind) { fprintf(stderr, "usage: %s [options]\n", argv[0]); exit(ERROR_USAGE); } return(0); } get_input_line() { char *nl; if (!fgets(input_line, sizeof input_line, stdin)) return(0); lineno++; nl = index(input_line, '\n'); if (!nl) { fprintf(stderr, "input line %d: too long or unterminated\n", lineno); exit(ERROR_USAGE); } *nl = '\0'; return(1); } get_input_line_noeof() { int rc; rc = get_input_line(); if (!rc) { fprintf(stderr, "error: premature EOF in input\n"); exit(ERROR_USAGE); } } cmgw_callback() { /* skip empty lines */ if (at_response[1]) puts(at_response+1); } process_record() { int msgstat; u_char pdubin[176]; int cc, scalen; char send_cmd[32]; if (!get_input_line()) return(0); if (!strcmp(input_line, "Received unread message:")) msgstat = 0; else if (!strcmp(input_line, "Received message:")) msgstat = 1; else if (!strcmp(input_line, "Stored unsent message:")) msgstat = 2; else if (!strcmp(input_line, "Sent message:")) msgstat = 3; else { fprintf(stderr, "input line %d: expected beginning of message record\n", lineno); exit(ERROR_USAGE); } for (;;) { get_input_line_noeof(); if (!isupper(input_line[0])) break; if (!index(input_line, ':')) break; } cc = decode_hex_line(input_line, pdubin, sizeof pdubin); if (cc < 1) { inv: fprintf(stderr, "input line %d: not a valid PDU\n", lineno); exit(ERROR_USAGE); } scalen = pdubin[0] + 1; if (cc < scalen + 1) goto inv; /* good to go */ sprintf(send_cmd, "AT+CMGW=%u,%d", cc - scalen, msgstat); atinterf_exec_cmd_needok(send_cmd, input_line, cmgw_callback); /* expect blank line after each PDU */ get_input_line_noeof(); if (input_line[0]) { fprintf(stderr, "input line %d: expected blank line after PDU\n", lineno); exit(ERROR_USAGE); } return(1); } main(argc, argv) char **argv; { process_cmdline(argc, argv); atinterf_init(); /* enable verbose error messages */ atinterf_exec_cmd_needok("AT+CMEE=2", 0, 0); /* set PDU mode */ atinterf_exec_cmd_needok("AT+CMGF=0", 0, 0); /* process stdin */ while (process_record()) ; exit(0); }