$ arv-run grep -H -n ATTGGAGGAAAGATGAGTGAC \< *.fastq \> output.txt
[...]
 1 stderr run-command: grep -H -n ATTGGAGGAAAGATGAGTGAC < /keep/3229739b505d2b878b62aed09895a55a+142/HWI-ST1027_129_D0THKACXX.1_1.fastq > output.txt
 2 stderr run-command: grep -H -n ATTGGAGGAAAGATGAGTGAC < /keep/3229739b505d2b878b62aed09895a55a+142/HWI-ST1027_129_D0THKACXX.1_2.fastq > output.txt
 2 stderr run-command: completed with exit code 0 (success)
 2 stderr run-command: the following output files will be saved to keep:
 2 stderr run-command: 121 ./output.txt
 2 stderr run-command: start writing output to keep
 1 stderr run-command: completed with exit code 0 (success)
 1 stderr run-command: the following output files will be saved to keep:
 1 stderr run-command: 363 ./output.txt
 1 stderr run-command: start writing output to keep
 2 stderr upload wrote 121 total 121
 1 stderr upload wrote 363 total 363
[..]