hadd(1) General Commands Manual hadd(1)

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.

Append to the output
Force overwriting of output file
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
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)
The compression level use is the one specified in the first input
Skip corrupt or non-existent files, do not exit
Re-optimize basket size when merging TTree
Do not merge Trees
Explicitly set the verbosity level: 0 request no output, 99 is the
default
Parallelize the execution in 'J' processes. If the number of processes
is not specified, use the system maximum.
Enable verbosity. If -j was specified, do not not delete partial files
stored inside working directory.
Carry out the partial multiprocess execution in the specified
directory
Open at most 'N' files at once (use 0 to request to use the system
maximum)
Resize the prefetching cache use to speed up I/O operations (use 0 to
disable)
Used with an argument provided, enables the corresponding experimental
feature for output trees. See ROOT::Experimental::EIOFeatures
Target file
Source files