Welcome To External Sorting Library Project

This is a C/C++ library for out of core sorting. The main API function in this library is ExSort . The usage of this API function is shown below. An implementation of an external sorting program ex-sort is also available. Its usage is also shown below.

Download

The API is currently well tested in 32-bit machines. Currently binary versions are available or GNU/Linux/i686 (libexsort.a). If you want to build on other platforms please download the source at (release.0.9.src.tgz). The source should be compiled with any C compiler supporting C99 standards. You can always checkout a last copy of the source code using cvs as follows.

cvs -d:pserver:anonymous@lib-ex-sort.cvs.sourceforge.net:/cvsroot/lib-ex-sort co lib-ex-sort

Usage of the API function.

Download the library (libexsort.a) or build it from the source and include the header file ExternalSortAPI.h in your compiler include path to use it.

DESC: External Sort API function.
INPUT:
1.  in_file: name of the file containing keys to sort.
2. out_file: name of the file to save the sorted keys.
3. KEY_SIZE: size of each key in bytes, 
4. col_start: the bytes between [col_start, col_end] will be used
              used to compare the keys during sorting. 
5. col_end:  see above. 
6. endian: either 0 or 1 (if 0 sorts the bytes between [col_start, col_end]
           from left right, otherwise sorts from right to left).

=============================================
void ExSort(const char *in_file, const char *out_file, unsigned char KEY_SIZE,
            unsigned char col_start, unsigned char col_end, unsigned char endian);
=============================================

Usage of the sorting program.

USAGE: ./ex-sort {KEY_SIZE} {SORT-KEY-START} {SORT-KEY-END} {in-file} {out-file} {endian}

The following shows an example on how to use the ex-sort program to sort a text file with fixed with keys of 36 bytes (37 including the new line). The following example shows the use of ex-sort to sort the first two bytes of each key.

vamsik-desktop:/media/Iomega_HDD/lib-ex-sort$ head test_case.1.txt 
GCTTTTAGTTTTCTGTAAGTTTTGCTCTTTTGGATA
TGTCATTGCTTACTCTTCACAAATGTTTACGTGTAA
GGGAGAAAAAACTTCAAACAGACATCAACATGGCCA
TTCATTTGGAAGACGAAACAGTTATCCCCGGAAATG
CCACCGCTGCATCCTGAGAACGTGCCGGTCGGGTGG
CTATCTATTATAGTCACATAATAGACATTAACAAAG
GTATATGACTACGAATGTATATTTTGTAATATTATT
GGGGATACTCTCGAGCTGGTTATGATAAAGTGACGT
ATGAATTATTATATACTATGTTTTTTTCTTACATTA
TGGATTTTGTAGTCAAGTCTTCATGTTTGATCTATG


vamsik-desktop:/media/Iomega_HDD/lib-ex-sort$ ./ex-sort 37 0 1 test_case.1.txt test_case.1.sorted.txt 0
SIZE OF EACH KEY IS 37
EACH KEY WILL BE SORTED BETWEEN 0 AND 1 ENDIAN 0

[EX-SORT CREATED 1 RUNS] took 0 ticks
[FINAL-RUN] has 5104 keys
[R-WAY MERGE] took 0 ticks
Converting the runfile=./tmp-eQVshHL to output=test_case.1.sorted.txt


vamsik-desktop:/media/Iomega_HDD/lib-ex-sort$ head test_case.1.sorted.txt 
AATAGAAACGGATGGTCTGCAACAAAATCTATTTCA
AAGATGACTTGATTGATTATTTTCCATGAACGAATC
AATTCAATCTAACAGTATATACTACAAAAAAATGAT
AAGGGTAGATTACTTAAAAGGAGTGTGTTTGGTTAG
AAAAAAAAACTAGCATGTATGGTACTTCTCTTACGA
AACAGGCGATCTCTAAACTTCGCCTAGTGTCTTTAT
AAAGAAAATAATCTTCATACTAGTCTTACACTCTTG
AAACGCACGAAACAAAAAAAAAAAAACGATCCGAAA
AAAAATATTAGCAAAGGTCCAACATTTTTTTGTGTA
AACCCAAAAATATCAGATTTTGGATTGGCTCGGATG

Questions

If you have any questions please email vamsik {at} engr uconn edu.