src/gromacs/utility/futil.h

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  37 /*! \file
  38  * \brief
  39  * Low-level wrappers for OS-specific file handling with some \Gromacs
  40  * customizations.
  41  *
  42  * \inpublicapi
  43  * \ingroup module_utility
  44  */
  45 #ifndef GMX_UTILITY_FUTIL_H
  46 #define GMX_UTILITY_FUTIL_H
  47
  48 #include <limits.h>
  49 #include <stdio.h>
  50
  51 #include "gromacs/utility/basedefinitions.h"
  52
  53 #ifdef __cplusplus
  54 extern "C" {
  55 #endif
  56 #if 0
  57 }
  58 #endif
  59
  60 /*! \def GMX_PATH_MAX
  61  * \brief
  62  * Maximum path length, if the OS provides one, otherwise a fixed constant.
  63  */
  64 #ifdef PATH_MAX
  65 #  define GMX_PATH_MAX PATH_MAX
  66 #elif defined MAX_PATH
  67 #  define GMX_PATH_MAX MAX_PATH
  68 #else
  69 #  define GMX_PATH_MAX 4096
  70 #endif
  71
  72 /** \Gromacs definition to use instead of `off_t`. */
  73 typedef gmx_int64_t    gmx_off_t;
  74
  75 /*! \brief
  76  * Turn off buffering for output files (which is default) for debugging
  77  * purposes.
  78  *
  79  * This only has effect on files opened with gmx_ffopen().
  80  */
  81 void gmx_disable_file_buffering(void);
  82
  83 /*! \brief
  84  * Enables backups with the specified number of maximum backups.
  85  *
  86  * If \p count == 0, disables backups.  If not called, this is the default.
  87  * If \p count == -1, reads the count from an environment variable.
  88  *
  89  * This is not currently thread-safe, as it is only called during
  90  * initialization code.
  91  */
  92 void gmx_set_max_backup_count(int count);
  93
  94 /*! \brief
  95  * Check whether a path exists.
  96  *
  97  * \returns `TRUE` when \p fname exists.
  98  *
  99  * Note that this returns `TRUE` even if \p fname is a directory instead of a
 100  * file.
 101  */
 102 gmx_bool gmx_fexist(const char *fname);
 103
 104 /*! \brief
 105  * Makes a backup of file if the file exists.
 106  */
 107 void make_backup(const char *file);
 108
 109 /*! \brief
 110  * Opens a file, with \Gromacs-specific additions.
 111  *
 112  * If the file is in compressed format, opens a pipe which uncompresses the
 113  * file on the fly.  For this to work, gmx_ffclose() and frewind() should
 114  * always be used for files opened with gmx_ffopen() instead of fclose() and
 115  * rewind().  For compressed files, the \p file parameter should be passed
 116  * without the compressed extension; if that file is not found, then a few
 117  * compression extensions are tried.
 118  * Creates a backup if a file opened for writing already exists before
 119  * overwriting it.
 120  * A fatal error results if the file cannot be opened, for whatever reason.
 121  */
 122 FILE *gmx_ffopen(const char *file, const char *mode);
 123
 124 /** Closes a file opened with gmx_ffopen(). */
 125 int gmx_ffclose(FILE *fp);
 126
 127 /*! \brief
 128  * Wraps rewind() for files opened with gmx_ffopen().
 129  *
 130  * A fatal error results if this function is called for a pipe (a compressed
 131  * input file).
 132  */
 133 void frewind(FILE *fp);
 134
 135 /** OS-independent 64-bit fseek(). */
 136 int gmx_fseek(FILE *stream, gmx_off_t offset, int whence);
 137
 138 /** OS-independent 64-bit ftell(). */
 139 gmx_off_t gmx_ftell(FILE *stream);
 140
 141 /** OS-independent truncate(). */
 142 int gmx_truncate(const char *filename, gmx_off_t length);
 143
 144 /*! \brief
 145  * Finds full path for a library file.
 146  *
 147  * Searches first in the current directory, and then in the configured library
 148  * directories.
 149  * Fatal error results if the file is not found in any location.
 150  * The caller is responsible of freeing the returned string.
 151  */
 152 char *gmxlibfn(const char *file);
 153
 154 /*! \brief
 155  * Opens a library file for reading.
 156  *
 157  * Works as gmxlibfn(), except that it opens the file and returns a file
 158  * handle.
 159  */
 160 FILE *libopen(const char *file);
 161
 162 /*! \brief
 163  * More flexible gmxlibfn().
 164  *
 165  * Works as gmxlibfn(), but provides control whether the current working
 166  * directory is searched or not, and whether a missing file is a fatal error or
 167  * not.
 168  */
 169 char *low_gmxlibfn(const char *file, gmx_bool bAddCWD, gmx_bool bFatal);
 170
 171 /*! \brief
 172  * Alternative for libopen() that optionally does not exit.
 173  *
 174  * Works as libopen(), but provides control whether a missing file is a fatal
 175  * error or not.
 176  */
 177 FILE *low_libopen(const char *file, gmx_bool bFatal);
 178
 179
 180 /*! \brief
 181  * Creates unique name for temp file (wrapper around mkstemp) and opens it.
 182  *
 183  * \p buf should be at least 7 bytes long
 184  */
 185 FILE *gmx_fopen_temporary(char *buf);
 186
 187 /*! \brief
 188  * Creates unique name for temp file (wrapper around mkstemp).
 189  *
 190  * \p buf should be at least 7 bytes long
 191  */
 192 void gmx_tmpnam(char *buf);
 193
 194 /*! \brief
 195  * OS-independent rename().
 196  *
 197  * Renames/moves a file atomically, if the OS makes that available.
 198  */
 199 int gmx_file_rename(const char *oldname, const char *newname);
 200
 201 /*! \brief
 202  * Copies a file (data only) oldname to newname.
 203  *
 204  * If \p copy_if_empty is `FALSE`, the file won't be copied if it's empty.
 205  */
 206 int gmx_file_copy(const char *oldname, const char *newname, gmx_bool copy_if_empty);
 207
 208 /*! \brief
 209  * OS-independent fsync().
 210  *
 211  * Only use this during checkpointing!
 212  */
 213 int gmx_fsync(FILE *fp);
 214
 215 /*! \brief
 216  * OS-independent chdir().
 217  *
 218  * Exits with a fatal error if changing the directory fails.
 219  */
 220 void gmx_chdir(const char *directory);
 221 /*! \brief
 222  * OS-independent getcwd().
 223  *
 224  * Exits with a fatal error if the call fails.
 225  */
 226 void gmx_getcwd(char *buffer, size_t size);
 227
 228 #ifdef __cplusplus
 229 }
 230
 231 namespace gmx
 232 {
 233
 234 class DataFileFinder;
 235
 236 /*! \brief
 237  * Gets a finder for locating data files from share/top/.
 238  *
 239  * \returns Finder set with setLibraryFileFinder(), or a default finder.
 240  *
 241  * If setLibraryFileFinder() has not been called (or a `NULL` finder has been
 242  * set), a default finder is returned.
 243  * The default finder searches data files from the directory identified by the
 244  * global program context; it does not respect GMXLIB environment variable.
 245  * Calling initForCommandLine() sets a finder that respects GMXLIB.
 246  *
 247  * Does not throw.
 248  *
 249  * See setLibraryFileFinder() for thread safety.
 250  *
 251  * \ingroup module_utility
 252  */
 253 const DataFileFinder &getLibraryFileFinder();
 254 /*! \brief
 255  * Sets a finder for location data files from share/top/.
 256  *
 257  * \param[in] finder  finder to set
 258  *     (can be NULL to restore the default finder).
 259  *
 260  * The library does not take ownership of \p finder.
 261  * The provided object must remain valid until the global instance is changed
 262  * by another call to setLibraryFileFinder().
 263  *
 264  * The global instance is used by gmxlibfn() and libopen().
 265  *
 266  * This method is not thread-safe.  See setProgramContext(); the same
 267  * constraints apply here as well.
 268  *
 269  * Does not throw.
 270  */
 271 void setLibraryFileFinder(const DataFileFinder *finder);
 272
 273 } // namespace gmx
 274 #endif
 275
 276 #endif