Mercurial > ~dholland > hg > ag > index.cgi
view examples/dsl/redirect.cpp @ 7:57b2cc9b87f7
Use memcpy instead of strncpy when we know the length anyway.
Modern gcc seems to think it knows how to detect misuse of strncpy,
but it's wrong (in fact: very, very wrong) and the path of least
resistance is to not try to fight with it.
author | David A. Holland |
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date | Mon, 30 May 2022 23:47:52 -0400 |
parents | 607e3be6bad8 |
children |
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/***** AnaGram Programming Examples A Dos Script Language Redirection Class Module Copyright 1993 Parsifal Software. All Rights Reserved. This software is provided 'as-is', without any express or implied warranty. In no event will the authors be held liable for any damages arising from the use of this software. Permission is granted to anyone to use this software for any purpose, including commercial applications, and to alter it and redistribute it freely, subject to the following restrictions: 1. The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required. 2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software. 3. This notice may not be removed or altered from any source distribution. *****/ #include "redirect.h" #include "assert.h" #include "util.h" // Constructors redirect::redirect(int h) { int temp; handle = h; #if defined(__MSDOS__) || defined(__WINDOWS__) tmpnam(name); temp = open(name, O_CREAT | O_RDWR | O_TEXT, S_IREAD | S_IWRITE); #else /* tmpnam() is unsafe, and causes a warning from many Unix linkers */ strcpy(name, ".dsl.XXXXXX"); temp = mkstemp(name); #endif assert(temp >= 0); old_handle = dup(handle); dup2(temp, handle); close(temp); copy_flag = 0; // live } redirect::redirect(int h, char *file_name, int append_flag) { int temp; int flag; handle = h; temp = open(file_name, O_CREAT | O_RDWR | O_TEXT, S_IREAD | S_IWRITE); if (append_flag) lseek(temp, 0L, SEEK_END); name[0] = 0; assert(temp >= 0); old_handle = dup(handle); flag = dup2(temp, handle); assert(flag == 0); close(temp); copy_flag = 0; // live } void redirect::operator = (const redirect &r) { handle = r.handle; old_handle = r.old_handle; strcpy(name, r.name); copy_flag = r.copy_flag; } redirect::redirect(const redirect &r) { *this = r; copy_flag++; // memorex } // Destructor redirect::~redirect() { if (copy_flag) return; dup2(old_handle, handle); close(old_handle); if (name[0]) unlink(name); } // Save temporary file char *save_file(redirect &s) { assert(s.copy_flag == 0); char *result = memdup(s.name, 1+strlen(s.name)); s.name[0] = 0; return result; } // Extract content of file char *content(redirect &s) { long length = filelength(s.handle); long where = tell(s.handle); // Current file position unsigned n; char *result; assert(length < 65520L); n = (unsigned) (length + 1); result = new char[n]; assert(result != NULL); lseek(s.handle,0,0); n = read(s.handle, result, (unsigned) length); lseek(s.handle,where,0); // Restore file result[n] = 0; // Terminate string return result; }