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				https://github.com/eledio-devices/thirdparty-littlefs.git
				synced 2025-10-31 00:32:38 +01:00 
			
		
		
		
	LFS_O_SNAPSHOT brings back some of littlefs's idiosyncratic behavior removed in the changes to open file syncing in a form that may be more useful for users. LFS_O_SNAPSHOT allows you to open a "snapshot" of a file. This is a cheap, local copy of a file who's changes are not reflected on disk. Internally, snapshot files use the same mechanism as pending writes. A separate, copy-on-write CTZ skip-list is created, with read-only references to the existing data blocks until a write occurs. The difference is that snapshot files are not enrolled in the mlist, meaning they won't get updates from open file syncs, and during close their contents are simply discarded. As an extra benefit, LFS_O_CREAT | LFS_O_SNAPSHOT is equivalent to Linux's O_TMPFILE, making it easy to create temporary, unnamed files. This may be useful for embedded development, where unnamed flash-backed buffers may provide a slower, but larger, alternative to RAM-backed buffers.
		
			
				
	
	
		
			304 lines
		
	
	
		
			12 KiB
		
	
	
	
		
			TOML
		
	
	
	
	
	
			
		
		
	
	
			304 lines
		
	
	
		
			12 KiB
		
	
	
	
		
			TOML
		
	
	
	
	
	
| [[case]] # set/get attribute
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| code = '''
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|     lfs_format(&lfs, &cfg) => 0;
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|     lfs_mount(&lfs, &cfg) => 0;
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|     lfs_mkdir(&lfs, "hello") => 0;
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|     lfs_file_open(&lfs, &file, "hello/hello", LFS_O_WRONLY | LFS_O_CREAT) => 0;
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|     lfs_file_write(&lfs, &file, "hello", strlen("hello")) => strlen("hello");
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|     lfs_file_close(&lfs, &file);
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|     lfs_unmount(&lfs) => 0;
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| 
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|     lfs_mount(&lfs, &cfg) => 0;
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|     memset(buffer, 0, sizeof(buffer));
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|     lfs_setattr(&lfs, "hello", 'A', "aaaa",   4) => 0;
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|     lfs_setattr(&lfs, "hello", 'B', "bbbbbb", 6) => 0;
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|     lfs_setattr(&lfs, "hello", 'C', "ccccc",  5) => 0;
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|     lfs_getattr(&lfs, "hello", 'A', buffer,    4) => 4;
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|     lfs_getattr(&lfs, "hello", 'B', buffer+4,  6) => 6;
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|     lfs_getattr(&lfs, "hello", 'C', buffer+10, 5) => 5;
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|     assert(memcmp(buffer,    "aaaa",   4) == 0);
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|     assert(memcmp(buffer+4,  "bbbbbb", 6) == 0);
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|     assert(memcmp(buffer+10, "ccccc",  5) == 0);
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| 
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|     lfs_setattr(&lfs, "hello", 'B', "", 0) => 0;
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|     lfs_getattr(&lfs, "hello", 'A', buffer,    4) => 4;
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|     lfs_getattr(&lfs, "hello", 'B', buffer+4,  6) => 0;
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|     lfs_getattr(&lfs, "hello", 'C', buffer+10, 5) => 5;
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|     assert(memcmp(buffer,    "aaaa",         4) == 0);
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|     assert(memcmp(buffer+10, "ccccc",        5) == 0);
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| 
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|     lfs_removeattr(&lfs, "hello", 'B') => 0;
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|     lfs_getattr(&lfs, "hello", 'A', buffer,    4) => 4;
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|     lfs_getattr(&lfs, "hello", 'B', buffer+4,  6) => LFS_ERR_NOATTR;
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|     lfs_getattr(&lfs, "hello", 'C', buffer+10, 5) => 5;
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|     assert(memcmp(buffer,    "aaaa",         4) == 0);
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|     assert(memcmp(buffer+10, "ccccc",        5) == 0);
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| 
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|     lfs_setattr(&lfs, "hello", 'B', "dddddd", 6) => 0;
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|     lfs_getattr(&lfs, "hello", 'A', buffer,    4) => 4;
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|     lfs_getattr(&lfs, "hello", 'B', buffer+4,  6) => 6;
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|     lfs_getattr(&lfs, "hello", 'C', buffer+10, 5) => 5;
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|     assert(memcmp(buffer,    "aaaa",   4) == 0);
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|     assert(memcmp(buffer+4,  "dddddd", 6) == 0);
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|     assert(memcmp(buffer+10, "ccccc",  5) == 0);
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| 
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|     lfs_setattr(&lfs, "hello", 'B', "eee", 3) => 0;
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|     lfs_getattr(&lfs, "hello", 'A', buffer,    4) => 4;
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|     lfs_getattr(&lfs, "hello", 'B', buffer+4,  6) => 3;
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|     lfs_getattr(&lfs, "hello", 'C', buffer+10, 5) => 5;
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|     assert(memcmp(buffer,    "aaaa",  4) == 0);
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|     assert(memcmp(buffer+4,  "eee",   3) == 0);
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|     assert(memcmp(buffer+10, "ccccc", 5) == 0);
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| 
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|     lfs_setattr(&lfs, "hello", 'A', buffer, LFS_ATTR_MAX+1) => LFS_ERR_NOSPC;
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|     lfs_setattr(&lfs, "hello", 'B', "fffffffff", 9) => 0;
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|     lfs_getattr(&lfs, "hello", 'A', buffer,    4) => 4;
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|     lfs_getattr(&lfs, "hello", 'B', buffer+4,  6) => 9;
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|     lfs_getattr(&lfs, "hello", 'C', buffer+10, 5) => 5;
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| 
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|     lfs_unmount(&lfs) => 0;
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| 
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|     lfs_mount(&lfs, &cfg) => 0;
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|     memset(buffer, 0, sizeof(buffer));
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|     lfs_getattr(&lfs, "hello", 'A', buffer,    4) => 4;
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|     lfs_getattr(&lfs, "hello", 'B', buffer+4,  9) => 9;
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|     lfs_getattr(&lfs, "hello", 'C', buffer+13, 5) => 5;
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|     assert(memcmp(buffer,    "aaaa",      4) == 0);
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|     assert(memcmp(buffer+4,  "fffffffff", 9) == 0);
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|     assert(memcmp(buffer+13, "ccccc",     5) == 0);
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| 
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|     lfs_file_open(&lfs, &file, "hello/hello", LFS_O_RDONLY) => 0;
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|     lfs_file_read(&lfs, &file, buffer, sizeof(buffer)) => strlen("hello");
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|     assert(memcmp(buffer, "hello", strlen("hello")) == 0);
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|     lfs_file_close(&lfs, &file);
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|     lfs_unmount(&lfs) => 0;
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| '''
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| 
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| [[case]] # set/get root attribute
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| code = '''
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|     lfs_format(&lfs, &cfg) => 0;
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|     lfs_mount(&lfs, &cfg) => 0;
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|     lfs_mkdir(&lfs, "hello") => 0;
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|     lfs_file_open(&lfs, &file, "hello/hello", LFS_O_WRONLY | LFS_O_CREAT) => 0;
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|     lfs_file_write(&lfs, &file, "hello", strlen("hello")) => strlen("hello");
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|     lfs_file_close(&lfs, &file);
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|     lfs_unmount(&lfs) => 0;
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| 
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|     lfs_mount(&lfs, &cfg) => 0;
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|     memset(buffer, 0, sizeof(buffer));
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|     lfs_setattr(&lfs, "/", 'A', "aaaa",   4) => 0;
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|     lfs_setattr(&lfs, "/", 'B', "bbbbbb", 6) => 0;
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|     lfs_setattr(&lfs, "/", 'C', "ccccc",  5) => 0;
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|     lfs_getattr(&lfs, "/", 'A', buffer,    4) => 4;
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|     lfs_getattr(&lfs, "/", 'B', buffer+4,  6) => 6;
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|     lfs_getattr(&lfs, "/", 'C', buffer+10, 5) => 5;
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|     assert(memcmp(buffer,    "aaaa",   4) == 0);
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|     assert(memcmp(buffer+4,  "bbbbbb", 6) == 0);
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|     assert(memcmp(buffer+10, "ccccc",  5) == 0);
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| 
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|     lfs_setattr(&lfs, "/", 'B', "", 0) => 0;
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|     lfs_getattr(&lfs, "/", 'A', buffer,    4) => 4;
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|     lfs_getattr(&lfs, "/", 'B', buffer+4,  6) => 0;
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|     lfs_getattr(&lfs, "/", 'C', buffer+10, 5) => 5;
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|     assert(memcmp(buffer,    "aaaa",  4) == 0);
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|     assert(memcmp(buffer+10, "ccccc", 5) == 0);
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| 
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|     lfs_removeattr(&lfs, "/", 'B') => 0;
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|     lfs_getattr(&lfs, "/", 'A', buffer,    4) => 4;
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|     lfs_getattr(&lfs, "/", 'B', buffer+4,  6) => LFS_ERR_NOATTR;
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|     lfs_getattr(&lfs, "/", 'C', buffer+10, 5) => 5;
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|     assert(memcmp(buffer,    "aaaa",  4) == 0);
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|     assert(memcmp(buffer+10, "ccccc", 5) == 0);
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| 
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|     lfs_setattr(&lfs, "/", 'B', "dddddd", 6) => 0;
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|     lfs_getattr(&lfs, "/", 'A', buffer,    4) => 4;
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|     lfs_getattr(&lfs, "/", 'B', buffer+4,  6) => 6;
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|     lfs_getattr(&lfs, "/", 'C', buffer+10, 5) => 5;
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|     assert(memcmp(buffer,    "aaaa",   4) == 0);
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|     assert(memcmp(buffer+4,  "dddddd", 6) == 0);
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|     assert(memcmp(buffer+10, "ccccc",  5) == 0);
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| 
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|     lfs_setattr(&lfs, "/", 'B', "eee", 3) => 0;
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|     lfs_getattr(&lfs, "/", 'A', buffer,    4) => 4;
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|     lfs_getattr(&lfs, "/", 'B', buffer+4,  6) => 3;
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|     lfs_getattr(&lfs, "/", 'C', buffer+10, 5) => 5;
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|     assert(memcmp(buffer,    "aaaa",  4) == 0);
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|     assert(memcmp(buffer+4,  "eee",   3) == 0);
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|     assert(memcmp(buffer+10, "ccccc", 5) == 0);
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| 
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|     lfs_setattr(&lfs, "/", 'A', buffer, LFS_ATTR_MAX+1) => LFS_ERR_NOSPC;
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|     lfs_setattr(&lfs, "/", 'B', "fffffffff", 9) => 0;
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|     lfs_getattr(&lfs, "/", 'A', buffer,    4) => 4;
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|     lfs_getattr(&lfs, "/", 'B', buffer+4,  6) => 9;
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|     lfs_getattr(&lfs, "/", 'C', buffer+10, 5) => 5;
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|     lfs_unmount(&lfs) => 0;
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| 
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|     lfs_mount(&lfs, &cfg) => 0;
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|     memset(buffer, 0, sizeof(buffer));
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|     lfs_getattr(&lfs, "/", 'A', buffer,    4) => 4;
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|     lfs_getattr(&lfs, "/", 'B', buffer+4,  9) => 9;
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|     lfs_getattr(&lfs, "/", 'C', buffer+13, 5) => 5;
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|     assert(memcmp(buffer,    "aaaa",      4) == 0);
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|     assert(memcmp(buffer+4,  "fffffffff", 9) == 0);
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|     assert(memcmp(buffer+13, "ccccc",     5) == 0);
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| 
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|     lfs_file_open(&lfs, &file, "hello/hello", LFS_O_RDONLY) => 0;
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|     lfs_file_read(&lfs, &file, buffer, sizeof(buffer)) => strlen("hello");
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|     assert(memcmp(buffer, "hello", strlen("hello")) == 0);
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|     lfs_file_close(&lfs, &file);
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|     lfs_unmount(&lfs) => 0;
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| '''
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| 
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| [[case]] # set/get file attribute
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| code = '''
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|     lfs_format(&lfs, &cfg) => 0;
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|     lfs_mount(&lfs, &cfg) => 0;
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|     lfs_mkdir(&lfs, "hello") => 0;
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|     lfs_file_open(&lfs, &file, "hello/hello", LFS_O_WRONLY | LFS_O_CREAT) => 0;
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|     lfs_file_write(&lfs, &file, "hello", strlen("hello")) => strlen("hello");
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|     lfs_file_close(&lfs, &file);
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|     lfs_unmount(&lfs) => 0;
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| 
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|     lfs_mount(&lfs, &cfg) => 0;
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|     memset(buffer, 0, sizeof(buffer));
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|     struct lfs_attr attrs1[] = {
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|         {'A', buffer,    4},
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|         {'B', buffer+4,  6},
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|         {'C', buffer+10, 5},
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|     };
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|     struct lfs_file_config cfg1 = {.attrs=attrs1, .attr_count=3};
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| 
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|     lfs_file_opencfg(&lfs, &file, "hello/hello", LFS_O_WRONLY, &cfg1) => 0;
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|     memcpy(buffer,    "aaaa",   4);
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|     memcpy(buffer+4,  "bbbbbb", 6);
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|     memcpy(buffer+10, "ccccc",  5);
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|     lfs_file_write(&lfs, &file, "hi", 2) => 2;
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|     lfs_file_close(&lfs, &file) => 0;
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|     memset(buffer, 0, 15);
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|     lfs_file_opencfg(&lfs, &file, "hello/hello", LFS_O_RDONLY, &cfg1) => 0;
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|     lfs_file_close(&lfs, &file) => 0;
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|     assert(memcmp(buffer,    "aaaa",   4) == 0);
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|     assert(memcmp(buffer+4,  "bbbbbb", 6) == 0);
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|     assert(memcmp(buffer+10, "ccccc",  5) == 0);
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| 
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|     attrs1[1].size = 0;
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|     lfs_file_opencfg(&lfs, &file, "hello/hello", LFS_O_WRONLY, &cfg1) => 0;
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|     lfs_file_write(&lfs, &file, "hi", 2) => 2;
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|     lfs_file_close(&lfs, &file) => 0;
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|     memset(buffer, 0, 15);
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|     attrs1[1].size = 6;
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|     lfs_file_opencfg(&lfs, &file, "hello/hello", LFS_O_RDONLY, &cfg1) => 0;
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|     lfs_file_close(&lfs, &file) => 0;
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|     assert(memcmp(buffer,    "aaaa",  4) == 0);
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|     assert(memcmp(buffer+10, "ccccc", 5) == 0);
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| 
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|     attrs1[1].size = 6;
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|     lfs_file_opencfg(&lfs, &file, "hello/hello", LFS_O_WRONLY, &cfg1) => 0;
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|     memcpy(buffer+4,  "dddddd", 6);
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|     lfs_file_write(&lfs, &file, "hi", 2) => 2;
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|     lfs_file_close(&lfs, &file) => 0;
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|     memset(buffer, 0, 15);
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|     attrs1[1].size = 6;
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|     lfs_file_opencfg(&lfs, &file, "hello/hello", LFS_O_RDONLY, &cfg1) => 0;
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|     lfs_file_close(&lfs, &file) => 0;
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|     assert(memcmp(buffer,    "aaaa",   4) == 0);
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|     assert(memcmp(buffer+4,  "dddddd", 6) == 0);
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|     assert(memcmp(buffer+10, "ccccc",  5) == 0);
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| 
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|     attrs1[1].size = 3;
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|     lfs_file_opencfg(&lfs, &file, "hello/hello", LFS_O_WRONLY, &cfg1) => 0;
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|     memcpy(buffer+4,  "eee", 3);
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|     lfs_file_write(&lfs, &file, "hi", 2) => 2;
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|     lfs_file_close(&lfs, &file) => 0;
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|     memset(buffer, 0, 15);
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|     attrs1[1].size = 6;
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|     lfs_file_opencfg(&lfs, &file, "hello/hello", LFS_O_RDONLY, &cfg1) => 0;
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|     lfs_file_close(&lfs, &file) => 0;
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|     assert(memcmp(buffer,    "aaaa",  4) == 0);
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|     assert(memcmp(buffer+4,  "eee",   3) == 0);
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|     assert(memcmp(buffer+10, "ccccc", 5) == 0);
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| 
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|     attrs1[0].size = LFS_ATTR_MAX+1;
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|     lfs_file_opencfg(&lfs, &file, "hello/hello2",
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|             LFS_O_WRONLY | LFS_O_CREAT, &cfg1) => LFS_ERR_NOSPC;
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| 
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|     struct lfs_attr attrs2[] = {
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|         {'A', buffer,    4},
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|         {'B', buffer+4,  9},
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|         {'C', buffer+13, 5},
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|     };
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|     struct lfs_file_config cfg2 = {.attrs=attrs2, .attr_count=3};
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|     lfs_file_opencfg(&lfs, &file, "hello/hello", LFS_O_RDWR, &cfg2) => 0;
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|     memcpy(buffer+4,  "fffffffff", 9);
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|     lfs_file_write(&lfs, &file, "hi", 2) => 2;
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|     lfs_file_close(&lfs, &file) => 0;
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|     attrs1[0].size = 4;
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|     lfs_file_opencfg(&lfs, &file, "hello/hello", LFS_O_RDONLY, &cfg1) => 0;
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|     lfs_file_close(&lfs, &file) => 0;
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| 
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|     lfs_unmount(&lfs) => 0;
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| 
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|     lfs_mount(&lfs, &cfg) => 0;
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|     memset(buffer, 0, sizeof(buffer));
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|     struct lfs_attr attrs3[] = {
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|         {'A', buffer,    4},
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|         {'B', buffer+4,  9},
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|         {'C', buffer+13, 5},
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|     };
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|     struct lfs_file_config cfg3 = {.attrs=attrs3, .attr_count=3};
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| 
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|     lfs_file_opencfg(&lfs, &file, "hello/hello", LFS_O_RDONLY, &cfg3) => 0;
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|     lfs_file_close(&lfs, &file) => 0;
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|     assert(memcmp(buffer,    "aaaa",      4) == 0);
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|     assert(memcmp(buffer+4,  "fffffffff", 9) == 0);
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|     assert(memcmp(buffer+13, "ccccc",     5) == 0);
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| 
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|     lfs_file_open(&lfs, &file, "hello/hello", LFS_O_RDONLY) => 0;
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|     lfs_file_read(&lfs, &file, buffer, sizeof(buffer)) => strlen("hello");
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|     assert(memcmp(buffer, "hillo", strlen("hello")) == 0);
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|     lfs_file_close(&lfs, &file);
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|     lfs_unmount(&lfs) => 0;
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| '''
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| 
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| [[case]] # deferred file attributes
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| code = '''
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|     lfs_format(&lfs, &cfg) => 0;
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|     lfs_mount(&lfs, &cfg) => 0;
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|     lfs_mkdir(&lfs, "hello") => 0;
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|     lfs_file_open(&lfs, &file, "hello/hello", LFS_O_WRONLY | LFS_O_CREAT) => 0;
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|     lfs_file_write(&lfs, &file, "hello", strlen("hello")) => strlen("hello");
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|     lfs_file_close(&lfs, &file);
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|     lfs_unmount(&lfs) => 0;
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| 
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|     lfs_mount(&lfs, &cfg) => 0;
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|     lfs_setattr(&lfs, "hello/hello", 'B', "fffffffff",  9) => 0;
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|     lfs_setattr(&lfs, "hello/hello", 'C', "ccccc",      5) => 0;
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| 
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|     memset(buffer, 0, sizeof(buffer));
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|     struct lfs_attr attrs1[] = {
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|         {'B', "gggg", 4},
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|         {'C', "",     0},
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|         {'D', "hhhh", 4},
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|     };
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|     struct lfs_file_config cfg1 = {.attrs=attrs1, .attr_count=3};
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| 
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|     lfs_file_opencfg(&lfs, &file, "hello/hello", LFS_O_WRONLY, &cfg1) => 0;
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| 
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|     lfs_getattr(&lfs, "hello/hello", 'B', buffer,    9) => 9;
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|     lfs_getattr(&lfs, "hello/hello", 'C', buffer+9,  9) => 5;
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|     lfs_getattr(&lfs, "hello/hello", 'D', buffer+18, 9) => LFS_ERR_NOATTR;
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|     assert(memcmp(buffer,    "fffffffff", 9) == 0);
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|     assert(memcmp(buffer+9,  "ccccc",     5) == 0);
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| 
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|     lfs_file_write(&lfs, &file, "hi", 2) => 2;
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|     lfs_file_sync(&lfs, &file) => 0;
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|     lfs_getattr(&lfs, "hello/hello", 'B', buffer,    9) => 4;
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|     lfs_getattr(&lfs, "hello/hello", 'C', buffer+9,  9) => 0;
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|     lfs_getattr(&lfs, "hello/hello", 'D', buffer+18, 9) => 4;
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|     assert(memcmp(buffer,    "gggg", 4) == 0);
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|     assert(memcmp(buffer+18, "hhhh", 4) == 0);
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| 
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|     lfs_file_close(&lfs, &file) => 0;
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|     lfs_unmount(&lfs) => 0;
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| '''
 |