Snakefile

shell.executable("bash")

rule a:
    output:
        ensure("test.txt", non_empty=True)
    shell:
        "touch {output}"


rule b:
    output:
        ensure("test2.txt", non_empty=True)
    shell:
        "echo test > {output}"


sha256 = "9f86d081884c7d659a2feaa0c55ad015a3bf4f1b2b0b822cd15d6c15b0f00a08"


rule c:
    output:
        ensure("test3.txt", sha256=sha256)
    shell:
        "echo -n test > {output}"


rule d:
    output:
        ensure("test4.txt", sha256=lambda w: sha256)
    shell:
        "echo -n test2 > {output}"