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578bfd0a AL |
1 | // -*- mode: cpp; mode: fold -*- |
2 | // Description /*{{{*/ | |
f55a958f | 3 | // $Id: fileutl.cc,v 1.2 1998/07/04 05:57:41 jgg Exp $ |
578bfd0a AL |
4 | /* ###################################################################### |
5 | ||
6 | File Utilities | |
7 | ||
8 | CopyFile - Buffered copy of a single file | |
9 | GetLock - dpkg compatible lock file manipulation (fcntl) | |
10 | ||
11 | This source is placed in the Public Domain, do with it what you will | |
12 | It was originally written by Jason Gunthorpe. | |
13 | ||
14 | ##################################################################### */ | |
15 | /*}}}*/ | |
16 | // Include Files /*{{{*/ | |
f55a958f | 17 | #include <pkglib/fileutl.h> |
578bfd0a AL |
18 | #include <pkglib/error.h> |
19 | ||
20 | #include <unistd.h> | |
21 | #include <sys/stat.h> | |
22 | #include <sys/fcntl.h> | |
23 | #include <sys/types.h> | |
24 | /*}}}*/ | |
25 | ||
26 | // CopyFile - Buffered copy of a file /*{{{*/ | |
27 | // --------------------------------------------------------------------- | |
28 | /* The caller is expected to set things so that failure causes erasure */ | |
29 | bool CopyFile(File From,File To) | |
30 | { | |
31 | if (From.IsOpen() == false || To.IsOpen() == false) | |
32 | return false; | |
33 | ||
34 | // Buffered copy between fds | |
35 | unsigned char *Buf = new unsigned char[64000]; | |
36 | long Size; | |
37 | while ((Size = read(From.Fd(),Buf,64000)) > 0) | |
38 | { | |
39 | if (To.Write(Buf,Size) == false) | |
40 | { | |
41 | delete [] Buf; | |
42 | return false; | |
43 | } | |
44 | } | |
45 | ||
46 | delete [] Buf; | |
47 | return true; | |
48 | } | |
49 | /*}}}*/ | |
50 | // GetLock - Gets a lock file /*{{{*/ | |
51 | // --------------------------------------------------------------------- | |
52 | /* This will create an empty file of the given name and lock it. Once this | |
53 | is done all other calls to GetLock in any other process will fail with | |
54 | -1. The return result is the fd of the file, the call should call | |
55 | close at some time. */ | |
56 | int GetLock(string File,bool Errors) | |
57 | { | |
58 | int FD = open(File.c_str(),O_RDWR | O_CREAT | O_TRUNC,0640); | |
59 | if (FD < 0) | |
60 | { | |
61 | if (Errors == true) | |
62 | _error->Errno("open","Could not open lock file %s",File.c_str()); | |
63 | return -1; | |
64 | } | |
65 | ||
66 | // Aquire a write lock | |
67 | struct flock fl; | |
68 | fl.l_type= F_WRLCK; | |
69 | fl.l_whence= SEEK_SET; | |
70 | fl.l_start= 0; | |
71 | fl.l_len= 1; | |
72 | if (fcntl(FD,F_SETLK,&fl) == -1) | |
73 | { | |
74 | if (Errors == true) | |
75 | _error->Errno("open","Could not get lock %s",File.c_str()); | |
76 | close(FD); | |
77 | return -1; | |
78 | } | |
79 | ||
80 | return FD; | |
81 | } | |
82 | /*}}}*/ | |
83 | // FileExists - Check if a file exists /*{{{*/ | |
84 | // --------------------------------------------------------------------- | |
85 | /* */ | |
86 | bool FileExists(string File) | |
87 | { | |
88 | struct stat Buf; | |
89 | if (stat(File.c_str(),&Buf) != 0) | |
90 | return false; | |
91 | return true; | |
92 | } | |
93 | /*}}}*/ | |
94 | // SafeGetCWD - This is a safer getcwd that returns a dynamic string /*{{{*/ | |
95 | // --------------------------------------------------------------------- | |
96 | /* We return / on failure. */ | |
97 | string SafeGetCWD() | |
98 | { | |
99 | // Stash the current dir. | |
100 | char S[300]; | |
101 | S[0] = 0; | |
102 | if (getcwd(S,sizeof(S)) == 0) | |
103 | return "/"; | |
104 | return S; | |
105 | } | |
106 | /*}}}*/ | |
107 | ||
108 | // File::File - Open a file /*{{{*/ | |
109 | // --------------------------------------------------------------------- | |
110 | /* The most commonly used open mode combinations are given with Mode */ | |
111 | File::File(string FileName,OpenMode Mode, unsigned long Perms) | |
112 | { | |
113 | Flags = 0; | |
114 | switch (Mode) | |
115 | { | |
116 | case ReadOnly: | |
117 | iFd = open(FileName.c_str(),O_RDONLY); | |
118 | break; | |
119 | ||
120 | case WriteEmpty: | |
121 | unlink(FileName.c_str()); | |
122 | iFd = open(FileName.c_str(),O_RDWR | O_CREAT | O_EXCL,Perms); | |
123 | break; | |
124 | ||
125 | case WriteExists: | |
126 | iFd = open(FileName.c_str(),O_RDWR); | |
127 | break; | |
128 | } | |
129 | ||
130 | if (iFd < 0) | |
131 | _error->Errno("open","Could not open file %s",FileName.c_str()); | |
132 | else | |
133 | this->FileName = FileName; | |
134 | } | |
135 | /*}}}*/ | |
136 | // File::~File - Closes the file /*{{{*/ | |
137 | // --------------------------------------------------------------------- | |
138 | /* If the proper modes are selected then we close the Fd and possibly | |
139 | unlink the file on error. */ | |
140 | File::~File() | |
141 | { | |
142 | Close(); | |
143 | } | |
144 | /*}}}*/ | |
145 | // File::Read - Read a bit of the file /*{{{*/ | |
146 | // --------------------------------------------------------------------- | |
147 | /* */ | |
148 | bool File::Read(void *To,unsigned long Size) | |
149 | { | |
150 | if (read(iFd,To,Size) != (signed)Size) | |
151 | { | |
152 | Flags |= Fail; | |
153 | return _error->Errno("read","Read error"); | |
154 | } | |
155 | ||
156 | return true; | |
157 | } | |
158 | /*}}}*/ | |
159 | // File::Write - Write to the file /*{{{*/ | |
160 | // --------------------------------------------------------------------- | |
161 | /* */ | |
162 | bool File::Write(void *From,unsigned long Size) | |
163 | { | |
164 | if (write(iFd,From,Size) != (signed)Size) | |
165 | { | |
166 | Flags |= Fail; | |
167 | return _error->Errno("write","Write error"); | |
168 | } | |
169 | ||
170 | return true; | |
171 | } | |
172 | /*}}}*/ | |
173 | // File::Seek - Seek in the file /*{{{*/ | |
174 | // --------------------------------------------------------------------- | |
175 | /* */ | |
176 | bool File::Seek(unsigned long To) | |
177 | { | |
178 | if (lseek(iFd,To,SEEK_SET) != (signed)To) | |
179 | { | |
180 | Flags |= Fail; | |
181 | return _error->Error("Unable to seek to %u",To); | |
182 | } | |
183 | ||
184 | return true; | |
185 | } | |
186 | /*}}}*/ | |
187 | // File::Size - Return the size of the file /*{{{*/ | |
188 | // --------------------------------------------------------------------- | |
189 | /* */ | |
190 | unsigned long File::Size() | |
191 | { | |
192 | struct stat Buf; | |
193 | if (fstat(iFd,&Buf) != 0) | |
194 | return _error->Errno("fstat","Unable to determine the file size"); | |
195 | return Buf.st_size; | |
196 | } | |
197 | /*}}}*/ | |
198 | // File::Close - Close the file if the close flag is set /*{{{*/ | |
199 | // --------------------------------------------------------------------- | |
200 | /* */ | |
201 | bool File::Close() | |
202 | { | |
203 | bool Res = true; | |
204 | if ((Flags & AutoClose) == AutoClose) | |
205 | if (close(iFd) != 0) | |
206 | Res &= _error->Errno("close","Problem closing the file"); | |
207 | ||
208 | if ((Flags & Fail) == Fail && (Flags & DelOnFail) == DelOnFail && | |
209 | FileName.empty() == false) | |
210 | if (unlink(FileName.c_str()) != 0) | |
211 | Res &= _error->Warning("unlnk","Problem unlinking the file"); | |
212 | return Res; | |
213 | } | |
214 | /*}}}*/ |