.TH hadd 1 
.SH SYNOPSIS
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

.SH DESCRIPTION
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.
.SH OPTIONS
.IP -a
Append to the output
.IP -f
Force overwriting of output file
.IP -f[0-9]
Gives the ability to specify the compression level of the target file.
.IP
Default is 1 (kDefaultZLIB), 0 is uncompressed, 9 is maximum
.IP
compression (see TFile::TFile documentation). You can also specify the
.IP
full compresion algorithm, e.g. -f206
.IP -fk
Sets the target file to contain the baskets with the same compression
.IP
as the input files (unless -O is specified). Compresses the meta data
.IP
using the compression level specified in the first input or the
.IP
compression setting after fk (for example 206 when using -fk206)
.IP -ff
The compression level use is the one specified in the first input
.IP -k
Skip corrupt or non-existent files, do not exit
.IP -O
Re-optimize basket size when merging TTree
.IP -T
Do not merge Trees
.IP -v
Explicitly set the verbosity level: 0 request no output, 99 is the
.IP
default
.IP -j
Parallelize the execution in 'J' processes. If the number of processes
.IP
is not specified, use the system maximum.
.IP -dbg
Enable verbosity. If -j was specified, do not not delete partial files
.IP
stored inside working directory.
.IP -d
Carry out the partial multiprocess execution in the specified
.IP
directory
.IP -n
Open at most 'N' files at once (use 0 to request to use the system
.IP
maximum)
.IP -cachesize
Resize the prefetching cache use to speed up I/O operations (use 0 to
.IP
disable)
.IP -experimental-io-features
Used with an argument provided, enables the corresponding experimental
.IP
feature for output trees. See ROOT::Experimental::EIOFeatures
.IP TARGET
Target file
.IP SOURCES
Source files