Julia编程12：文件系统

# 当前目录
pwd()
# Julia获取正在运行的源程序文件所在的目录
dirname(@__FILE__) == "/Users/victor/"
# 切换目录
cd("/Users/victor/data")

# 将目录与文件连接成一个完整路径
joinpath(dirname(@__FILE__), "data", "pkg.csv") == "/Users/victor/data/pkg.csv"

abspath("pkg.csv") == "/Users/victor/data/pkg.csv" 

basename("/Users/victor/data/pkg.csv") == "pkg.csv" 

dirname("/Users/victor/data/pkg.csv") == "/Users/victor/data" 

normpath("/Users/victor/data/../pkg.csv")=="/Users/victor/pkg.csv"

splitext("/Users/victor/data/pkg.csv")
# ("/Users/victor/data/pkg", ".csv")
splitext("/Users/victor/data")
# ("/Users/victor/data", "")

splitpath("/Users/victor/data/pkg.csv")
# "/"
# "Users"
# "victor"
# "data"
# "pkg.csv"

ispath(filename) # 是否存在
isdir(filename) # 判断是否是目录
isfile(filename) # 判断是否是文件
islink(filename) # 判断是否是链接
isabspath(filename) # 判断是否是绝对路径

cd("data")
readdir() # 返回指定目录的文件和子目录列表
# 4-element Vector{String}:
#  "pkgs copy 2.csv"
#  "pkgs copy 3.csv"
#  "pkgs copy.csv"
#  "pkgs.csv"

readdir(join=true) #返回绝对路径
# 4-element Vector{String}:
#  "/Users/victor/data/pkgs copy 2.csv"
#  "/Users/victor/data/pkgs copy 3.csv"
#  "/Users/victor/data/pkgs copy.csv"
#  "/Users/victor/data/pkgs.csv"

cd("../")
pwd()=="/Users/victor"
readdir("data")
# 4-element Vector{String}:
#  "pkgs copy 2.csv"
#  "pkgs copy 3.csv"
#  "pkgs copy.csv"
#  "pkgs.csv"

readdir(abspath("data"), join=true)
#  4-element Vector{String}:
#  "/Users/victor/data/pkgs copy 2.csv"
#  "/Users/victor/data/pkgs copy 3.csv"
#  "/Users/victor/data/pkgs copy.csv"
#  "/Users/victor/data/pkgs.csv"

walkdir(path) # 返回一个可迭代对象，包括当前目录、其中的子目录列表、其中的文件列表。
for (root, dirs, files) in walkdir("data")
    println("Directories in $root")
    for dir in dirs
        println(joinpath(root, dir)) # path to directories
    end
    println("Files in $root")
    for file in files
        println(joinpath(root, file)) # path to files
    end
end
# Directories in data
# Files in data
# data/pkgs copy 2.csv
# data/pkgs copy 3.csv
# data/pkgs copy.csv
# data/pkgs.csv

# 如果目录已经存在会报错
mkdir("newdir/newdir2")

# 如果目录已经存在不会报错
mkpath("newdir/newdir2")

touch("newfile.csv")

hardlink("/Users/victor/data/pkg.csv", "/Users/victor/pkg.csv")

symlink("/Users/victor/data/pkg.csv", "/Users/victor/pkg.csv")

cp("/Users/victor/data/pkg.csv", "/Users/victor/pkg.csv";force=true)
mv("/Users/victor/data/pkg.csv", "/Users/victor/pkg.csv";force=true)

# 删除文件
rm("/Users/victor/data/pkg.csv")
# 删除目录
rm("/Users/victor/data", recursive=true)
# force=true，不存在的文件不会报错
rm("/Users/victor/data/no.csv", force=true)

download("", "/Users/victor/data")

https://docs.julialang.org/en/v1/base/file/