Ignore symbolic links unless --force specified

programs/util.h

@@ -1,6 +1,6 @@
 /**
  * util.h - utility functions
- * 
+ *
  * Copyright (c) 2016-present, Przemyslaw Skibinski, Yann Collet, Facebook, Inc.
  * All rights reserved.
  *
@@ -228,6 +228,20 @@ UTIL_STATIC U32 UTIL_isDirectory(const char* infilename)
     return 0;
 }
 
+UTIL_STATIC U32 UTIL_isLink(const char* infilename)
+{
+#if defined(_WIN32)
+    /* no symlinks on windows */
+    (void)infilename;
+#else
+    int r;
+    stat_t statbuf;
+    r = lstat(infilename, &statbuf);
+    if (!r && S_ISLNK(statbuf.st_mode)) return 1;
+#endif
+    return 0;
+}
+
 
 UTIL_STATIC U64 UTIL_getFileSize(const char* infilename)
 {
@@ -271,11 +285,10 @@ UTIL_STATIC void *UTIL_realloc(void *ptr, size_t size)
     return NULL;
 }
 
-
 #ifdef _WIN32
 #  define UTIL_HAS_CREATEFILELIST
 
-UTIL_STATIC int UTIL_prepareFileList(const char *dirName, char** bufStart, size_t* pos, char** bufEnd)
+UTIL_STATIC int UTIL_prepareFileList(const char *dirName, char** bufStart, size_t* pos, char** bufEnd, int followLinks)
 {
     char* path;
     int dirLength, fnameLength, pathLength, nbFiles = 0;
@@ -311,7 +324,7 @@ UTIL_STATIC int UTIL_prepareFileList(const char *dirName, char** bufStart, size_
             if (strcmp (cFile.cFileName, "..") == 0 ||
                 strcmp (cFile.cFileName, ".") == 0) continue;
 
-            nbFiles += UTIL_prepareFileList(path, bufStart, pos, bufEnd);  /* Recursively call "UTIL_prepareFileList" with the new path. */
+            nbFiles += UTIL_prepareFileList(path, bufStart, pos, bufEnd, followLinks);  /* Recursively call "UTIL_prepareFileList" with the new path. */
             if (*bufStart == NULL) { free(path); FindClose(hFile); return 0; }
         }
         else if ((cFile.dwFileAttributes & FILE_ATTRIBUTE_NORMAL) || (cFile.dwFileAttributes & FILE_ATTRIBUTE_ARCHIVE) || (cFile.dwFileAttributes & FILE_ATTRIBUTE_COMPRESSED)) {
@@ -339,7 +352,11 @@ UTIL_STATIC int UTIL_prepareFileList(const char *dirName, char** bufStart, size_
 #  include <dirent.h>       /* opendir, readdir */
 #  include <string.h>       /* strerror, memcpy */
 
-UTIL_STATIC int UTIL_prepareFileList(const char *dirName, char** bufStart, size_t* pos, char** bufEnd)
+static int g_displayLevel;
+#define UTIL_DISPLAY(...)         fprintf(stderr, __VA_ARGS__)
+#define UTIL_DISPLAYLEVEL(l, ...) { if (g_displayLevel>=l) { UTIL_DISPLAY(__VA_ARGS__); } }
+
+UTIL_STATIC int UTIL_prepareFileList(const char *dirName, char** bufStart, size_t* pos, char** bufEnd, int followLinks)
 {
     DIR *dir;
     struct dirent *entry;
@@ -360,13 +377,19 @@ UTIL_STATIC int UTIL_prepareFileList(const char *dirName, char** bufStart, size_
         path = (char*) malloc(dirLength + fnameLength + 2);
         if (!path) { closedir(dir); return 0; }
         memcpy(path, dirName, dirLength);
+
         path[dirLength] = '/';
         memcpy(path+dirLength+1, entry->d_name, fnameLength);
         pathLength = dirLength+1+fnameLength;
         path[pathLength] = 0;
 
+        if (!followLinks && UTIL_isLink(path)) {
+            UTIL_DISPLAYLEVEL(2, "Warning : %s is a symbolic link, ignoring\n", path);
+            continue;
+        }
+
         if (UTIL_isDirectory(path)) {
-            nbFiles += UTIL_prepareFileList(path, bufStart, pos, bufEnd);  /* Recursively call "UTIL_prepareFileList" with the new path. */
+            nbFiles += UTIL_prepareFileList(path, bufStart, pos, bufEnd, followLinks);  /* Recursively call "UTIL_prepareFileList" with the new path. */
             if (*bufStart == NULL) { free(path); closedir(dir); return 0; }
         } else {
             if (*bufStart + *pos + pathLength >= *bufEnd) {
@@ -396,7 +419,7 @@ UTIL_STATIC int UTIL_prepareFileList(const char *dirName, char** bufStart, size_
 
 #else
 
-UTIL_STATIC int UTIL_prepareFileList(const char *dirName, char** bufStart, size_t* pos, char** bufEnd)
+UTIL_STATIC int UTIL_prepareFileList(const char *dirName, char** bufStart, size_t* pos, char** bufEnd, int followLinks)
 {
     (void)bufStart; (void)bufEnd; (void)pos;
     fprintf(stderr, "Directory %s ignored (compiled without _WIN32 or _POSIX_C_SOURCE)\n", dirName);
@@ -411,7 +434,7 @@ UTIL_STATIC int UTIL_prepareFileList(const char *dirName, char** bufStart, size_
  * After finishing usage of the list the structures should be freed with UTIL_freeFileList(params: return value, allocatedBuffer)
  * In case of error UTIL_createFileList returns NULL and UTIL_freeFileList should not be called.
  */
-UTIL_STATIC const char** UTIL_createFileList(const char **inputNames, unsigned inputNamesNb, char** allocatedBuffer, unsigned* allocatedNamesNb)
+UTIL_STATIC const char** UTIL_createFileList(const char **inputNames, unsigned inputNamesNb, char** allocatedBuffer, unsigned* allocatedNamesNb, int followLinks)
 {
     size_t pos;
     unsigned i, nbFiles;
@@ -436,7 +459,7 @@ UTIL_STATIC const char** UTIL_createFileList(const char **inputNames, unsigned i
                 nbFiles++;
             }
         } else {
-            nbFiles += UTIL_prepareFileList(inputNames[i], &buf, &pos, &bufend);
+            nbFiles += UTIL_prepareFileList(inputNames[i], &buf, &pos, &bufend, followLinks);
             if (buf == NULL) return NULL;
     }   }
 

programs/zstd.1

@@ -1,5 +1,5 @@
 .
-.TH "ZSTD" "1" "March 2017" "zstd 1.1.4" "User Commands"
+.TH "ZSTD" "1" "March 2017" "zstd 1.1.5" "User Commands"
 .
 .SH "NAME"
 \fBzstd\fR \- zstd, unzstd, zstdcat \- Compress or decompress \.zst files
@@ -110,7 +110,7 @@ save result into \fBfile\fR (only possible with a single INPUT\-FILE)
 .
 .TP
 \fB\-f\fR, \fB\-\-force\fR
-overwrite output without prompting
+overwrite output without prompting, and (de)compress symbolic links
 .
 .TP
 \fB\-c\fR, \fB\-\-stdout\fR

programs/zstd.1.md

@@ -108,7 +108,7 @@ the last one takes effect.
 * `-o file`:
     save result into `file` (only possible with a single INPUT-FILE)
 * `-f`, `--force`:
-    overwrite output without prompting
+    overwrite output without prompting, and (de)compress symbolic links
 * `-c`, `--stdout`:
     force write to standard output, even if it is the console
 * `--[no-]sparse`:

programs/zstdcli.c

@@ -99,7 +99,7 @@ static int usage(const char* programName)
 #endif
     DISPLAY( " -D file: use `file` as Dictionary \n");
     DISPLAY( " -o file: result stored into `file` (only if 1 input file) \n");
-    DISPLAY( " -f     : overwrite output without prompting \n");
+    DISPLAY( " -f     : overwrite output without prompting and (de)compress links \n");
     DISPLAY( "--rm    : remove source file(s) after successful de/compression \n");
     DISPLAY( " -k     : preserve source file(s) (default) \n");
     DISPLAY( " -h/-H  : display help/long help and exit\n");
@@ -270,6 +270,7 @@ int main(int argCount, const char* argv[])
 {
     int argNb,
         forceStdout=0,
+        followLinks=0,
         main_pause=0,
         nextEntryIsDictionary=0,
         operationResult=0,
@@ -357,7 +358,7 @@ int main(int argCount, const char* argv[])
                     if (!strcmp(argument, "--compress")) { operation=zom_compress; continue; }
                     if (!strcmp(argument, "--decompress")) { operation=zom_decompress; continue; }
                     if (!strcmp(argument, "--uncompress")) { operation=zom_decompress; continue; }
-                    if (!strcmp(argument, "--force")) { FIO_overwriteMode(); continue; }
+                    if (!strcmp(argument, "--force")) { FIO_overwriteMode(); forceStdout=1; followLinks=1; continue; }
                     if (!strcmp(argument, "--version")) { g_displayOut=stdout; DISPLAY(WELCOME_MESSAGE); CLEAN_RETURN(0); }
                     if (!strcmp(argument, "--help")) { g_displayOut=stdout; CLEAN_RETURN(usage_advanced(programName)); }
                     if (!strcmp(argument, "--verbose")) { g_displayLevel++; continue; }
@@ -445,7 +446,7 @@ int main(int argCount, const char* argv[])
                     case 'D': nextEntryIsDictionary = 1; lastCommand = 1; argument++; break;
 
                         /* Overwrite */
-                    case 'f': FIO_overwriteMode(); forceStdout=1; argument++; break;
+                    case 'f': FIO_overwriteMode(); forceStdout=1; followLinks=1; argument++; break;
 
                         /* Verbose mode */
                     case 'v': g_displayLevel++; argument++; break;
@@ -581,9 +582,21 @@ int main(int argCount, const char* argv[])
     DISPLAYLEVEL(4, "PLATFORM_POSIX_VERSION defined: %ldL\n", (long) PLATFORM_POSIX_VERSION);
 #endif
 
+
+    if (!followLinks) {
+        unsigned u;
+        for (u=0, fileNamesNb=0; u<filenameIdx; u++) {
+            if (UTIL_isLink(filenameTable[u])) {
+                DISPLAYLEVEL(2, "Warning : %s is a symbolic link, ignoring\n", filenameTable[u]);
+            } else {
+                filenameTable[fileNamesNb++] = filenameTable[u];
+            }
+        }
+        filenameIdx = fileNamesNb;
+    }
 #ifdef UTIL_HAS_CREATEFILELIST
     if (recursive) {  /* at this stage, filenameTable is a list of paths, which can contain both files and directories */
-        extendedFileList = UTIL_createFileList(filenameTable, filenameIdx, &fileNamesBuf, &fileNamesNb);
+        extendedFileList = UTIL_createFileList(filenameTable, filenameIdx, &fileNamesBuf, &fileNamesNb, followLinks);
         if (extendedFileList) {
             unsigned u;
             for (u=0; u<fileNamesNb; u++) DISPLAYLEVEL(4, "%u %s\n", u, extendedFileList[u]);

tests/playTests.sh

@@ -169,6 +169,19 @@ $ECHO "$ECHO foo | $ZSTD > /dev/full"
 $ECHO foo | $ZSTD > /dev/full && die "write error not detected!"
 $ECHO "$ECHO foo | $ZSTD | $ZSTD -d > /dev/full"
 $ECHO foo | $ZSTD | $ZSTD -d > /dev/full && die "write error not detected!"
+
+$ECHO "\n**** symbolic link test **** "
+
+rm -f hello.tmp world.tmp hello.tmp.zst world.tmp.zst
+$ECHO "hello world" > hello.tmp
+ln -s hello.tmp world.tmp
+$ZSTD world.tmp hello.tmp
+ls hello.tmp.zst || die "regular file should have been compressed!"
+ls world.tmp.zst && die "symbolic link should not have been compressed!"
+$ZSTD world.tmp hello.tmp -f
+ls world.tmp.zst || die "symbol link should have been compressed with --force"
+rm -f hello.tmp world.tmp hello.tmp.zst world.tmp.zst
+
 fi
 
 

zlibWrapper/examples/zwrapbench.c

@@ -982,7 +982,7 @@ int main(int argCount, char** argv)
 
 #ifdef UTIL_HAS_CREATEFILELIST
     if (recursive) {
-        fileNamesTable = UTIL_createFileList(filenameTable, filenameIdx, &fileNamesBuf, &fileNamesNb);
+        fileNamesTable = UTIL_createFileList(filenameTable, filenameIdx, &fileNamesBuf, &fileNamesNb, 1);
         if (fileNamesTable) {
             unsigned u;
             for (u=0; u<fileNamesNb; u++) DISPLAYLEVEL(4, "%u %s\n", u, fileNamesTable[u]);