FreeCalypso > hg > freecalypso-tools
view loadtools/lthelp.c @ 965:2969032bdfac
fcup-smsend[mult]: fix buglet in K&R C NULL pointer passing
The only 100% safe way to pass a NULL pointer as a function argument
in K&R C is to cast 0 to a pointer type; failing to do so may cause
mysterious bugs (invalid stack frames or garbage in argument registers)
on 64-bit machines. This issue has already been fixed in most of
FC host tools, but I just found some missed spots: passing of NULL UDH
to PDU encoding functions in fcup-smsend[mult] in the case of single
(not concatenated) SMS.
author | Mychaela Falconia <falcon@freecalypso.org> |
---|---|
date | Fri, 01 Sep 2023 07:33:51 +0000 |
parents | 464a531122ab |
children |
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/* * This module implements the loadtool help facility. */ #include <stdio.h> #include <ctype.h> #include <string.h> #include <strings.h> #include <stdlib.h> char loadtool_help_file[] = "/opt/freecalypso/helpfiles/loadtool.help"; loadtool_help(topic) char *topic; { FILE *f; char linebuf[256]; char *cp, *np; int flag; f = fopen(loadtool_help_file, "r"); if (!f) { perror(loadtool_help_file); return(-1); } for (;;) { if (!fgets(linebuf, sizeof linebuf, f)) { fprintf(stderr, "Help topic \"%s\" not found\n", topic); fclose(f); return(-1); } if (linebuf[0] != '=' || linebuf[1] != '=' || linebuf[2] != '=') continue; for (cp = linebuf + 3; isspace(*cp); cp++) ; for (np = cp; *cp && !isspace(*cp); cp++) ; if (*cp) *cp++ = '\0'; if (!strcmp(np, topic)) break; } for (flag = 0; fgets(linebuf, sizeof linebuf, f); ) { if (linebuf[0] == '=' && linebuf[1] == '=' && linebuf[2] == '=') { if (flag) break; else continue; } fputs(linebuf, stdout); flag = 1; } fclose(f); return(0); } cmd_help(argc, argv) char **argv; { char flashtopic[32]; switch (argc) { case 1: return loadtool_help("main"); case 2: return loadtool_help(argv[1]); case 3: if ((!strcmp(argv[1], "flash") || !strcmp(argv[1], "flash2")) && strlen(argv[2]) <= 20) { sprintf(flashtopic, "flash:%s", argv[2]); return loadtool_help(flashtopic); } fprintf(stderr, "No such help topic\n"); return(-1); default: fprintf(stderr, "internal error in cmd_help(): bad argc\n"); abort(); } }