v1.5.0

README.md

@@ -98,7 +98,7 @@ Copy gztool.c to the directory where you compiled zlib, and do:
 Usage
 =====
 
-      gztool (v1.4.3)
+      gztool (v1.5.0)
       GZIP files indexer, compressor and data retriever.
       Create small indexes for gzipped files and use them
       for quick and random-positioned data extraction.
@@ -129,7 +129,7 @@ Usage
      -e: if multiple files are indicated, continue on error (if any).
      -E: end processing on first GZIP end of file marker at EOF.
          Nonetheless with `-c`, `-E` waits for more data even at EOF.
-     -f: force file overwriting if destination file already exists.
+     -f: force file overwriting if index file already exists.
      -F: force index creation/completion first, and then action: if
          `-F` is not used, index is created interleaved with actions.
      -h: print brief help; `-hh` prints this help.
@@ -341,6 +341,14 @@ Take into account that, as shown, the first byte of the truncated `gzip_filename
 
 Please, note that index point positions at index file **may require also the previous byte** to be available in the truncated gzip file, as a gzip stream is not byte-rounded but a stream of pure bits. Thus **if you're thinking on truncating a gzip file, please do it always at least by one byte before the indicated index point in the gzip** - as said, it may not be needed, but in 7 of 8 cases it is needed.
 
+* Since v1.5.0, using `-[fW]` (`-f`: force index overwriting; `-W`: do not write index) with `-[ST]` (`-S`: create index on still-growing gzip file; `-T`: tail and continue decompressing to stdout) indicates `gztool` to continue operations even after the source file is overwritten. If using `-f`, the index file will be overwritten. For example:
+
+        $ gztool -WT log_filename.gz
+        ...
+        File overwriting detected and restarting decompression...
+        Processing 'log_filename.gz' ...
+
+
 Index file format
 =================
 
@@ -430,7 +438,7 @@ Other interesting links
 Version
 =======
 
-This version is **v1.4.3**.
+This version is **v1.5.0**.
 
 Please, read the *Disclaimer*. In case of any errors, please open an [issue](https://github.com/circulosmeos/gztool/issues).
 

gztool.1

@@ -4,7 +4,7 @@
 .\" First parameter, NAME, should be all caps
 .\" Second parameter, SECTION, should be 1-8, maybe w/ subsection
 .\" other parameters are allowed: see man(7), man(1)
-.TH gztool 1 "Sep 30 2021" "gztool v1.4.3"
+.TH gztool 1 "Jul 15 2022" "gztool v1.5.0"
 .\" Please adjust this date whenever revising the manpage.
 .\"
 .\" Some roff macros, for reference:
@@ -356,6 +356,19 @@ Take into account that, as shown, the first byte of the truncated `gzip_filename
 Please, note that index point positions at index file \fBmay require also the previous byte\fP to be available in the truncated gzip file, as gzip stream is not byte-rounded but a stream of pure bits. Thus \fIif you're thinking on truncating a gzip file, please do it always at least by one byte before the indicated index point in the gzip\fP - as said, it may not be needed, but in 7 of 8 cases it is needed.
 .br
 
+
+* Since v1.5.0, using `-[fW]` (`-f`: force index overwriting; `-W`: do not write index) with `-[ST]` (`-S`: create index on still-growing gzip file; `-T`: tail and continue decompressing to stdout) indicates `gztool` to continue operations even after the source file is overwritten. If using `-f`, the index file will be overwritten. For example:
+
+
+.BR \ \ \ \ $\ gztool\ -WT\ log_filename.gz
+.br
+.BR \ \ \ \ ...
+.br
+.BR \ \ \ \ File\ overwriting\ detected\ and\ restarting\ decompression...
+.br
+.BR \ \ \ \ Processing\ 'log_filename.gz' ...
+.br
+
 .SH INTERNALS
 By default gzip-compressed files cannot be accessed in random mode: any byte required at position N requires the complete gzip file to be decompressed from the beginning to the N byte.   
 Nonetheless Mark Adler, the author of zlib (//github.com/madler/zlib), provided years ago a cryptic file named `zran.c` (//github.com/madler/zlib/blob/master/examples/zran.c) that creates an "index" of "windows" filled with 32 kiB of uncompressed data at different positions along the un/compressed file, which can be used to initialize the zlib library and make it behave as if compressed data begin there.   

gztool.c

@@ -13,7 +13,7 @@
 //
 // LICENSE:
 //
-// v0.1 to v1.4* by Roberto S. Galende, 2019, 2020, 2021
+// v0.1 to v1.5* by Roberto S. Galende, 2019, 2020, 2021, 2022
 // //github.com/circulosmeos/gztool
 // A work by Roberto S. Galende 
 // distributed under the same License terms covering
@@ -123,7 +123,7 @@
     #include <config.h>
 #else
     #define PACKAGE_NAME "gztool"
-    #define PACKAGE_VERSION "1.4.3"
+    #define PACKAGE_VERSION "1.5.0"
 #endif
 
 #define _XOPEN_SOURCE 500 // expose <unistd.h>'s pread()