hadd - Man Page

usage: hadd [-a] [-f] [-f[0-9]] [-fk] [-ff] [-k] [-O] [-T] [-v V] [-j J]
           [-dbg] [-d D] [-n N] [-cachesize CACHESIZE]
           [-experimental-io-features EXPERIMENTAL_IO_FEATURES]
           TARGET SOURCES

This program will add histograms, trees and other objects from a list of ROOT files and write them to a target ROOT file. The target file is newly created and must not exist, or if -f ("force") is given, must not be one of the source files.

-a

Append to the output

-f

Force overwriting of output file

-f[0-9]

Gives the ability to specify the compression level of the target file.

Default is 1 (kDefaultZLIB), 0 is uncompressed, 9 is maximum

compression (see TFile::TFile documentation). You can also specify the

full compresion algorithm, e.g. -f206

-fk

Sets the target file to contain the baskets with the same compression

as the input files (unless -O is specified). Compresses the meta data

using the compression level specified in the first input or the

compression setting after fk (for example 206 when using -fk206)

-ff

The compression level use is the one specified in the first input

-k

Skip corrupt or non-existent files, do not exit

-O

Re-optimize basket size when merging TTree

-T

Do not merge Trees

-v

Explicitly set the verbosity level: 0 request no output, 99 is the

default

-j

Parallelize the execution in 'J' processes. If the number of processes

is not specified, use the system maximum.

-dbg

Enable verbosity. If -j was specified, do not not delete partial files

stored inside working directory.

-d

Carry out the partial multiprocess execution in the specified

directory

-n

Open at most 'N' files at once (use 0 to request to use the system

maximum)

-cachesize

Resize the prefetching cache use to speed up I/O operations (use 0 to

disable)

-experimental-io-features

Used with an argument provided, enables the corresponding experimental

feature for output trees. See ROOT::Experimental::EIOFeatures

TARGET

Target file

SOURCES

Source files