分类
shell

mktemp 生成临时文件或目录

Usage: mktemp [OPTION]... [TEMPLATE]
Create a temporary file or directory, safely, and print its name.
TEMPLATE must contain at least 3 consecutive 'X's in last component.
If TEMPLATE is not specified, use tmp.XXXXXXXXXX, and --tmpdir is implied.
Files are created u+rw, and directories u+rwx, minus umask restrictions.

  -d, --directory     create a directory, not a file
  -u, --dry-run       do not create anything; merely print a name (unsafe)
  -q, --quiet         suppress diagnostics about file/dir-creation failure
      --suffix=SUFF   append SUFF to TEMPLATE; SUFF must not contain a slash.
                        This option is implied if TEMPLATE does not end in X
  -p DIR, --tmpdir[=DIR]  interpret TEMPLATE relative to DIR; if DIR is not
                        specified, use $TMPDIR if set, else /tmp.  With
                        this option, TEMPLATE must not be an absolute name;
                        unlike with -t, TEMPLATE may contain slashes, but
                        mktemp creates only the final component
  -t                  interpret TEMPLATE as a single file name component,
                        relative to a directory: $TMPDIR, if set; else the
                        directory specified via -p; else /tmp [deprecated]
      --help     display this help and exit
      --version  output version information and exit

GNU coreutils online help: 
For complete documentation, run: info coreutils 'mktemp invocation'

分类
shell

shell 遍历 0-f

for i in `seq 0 15`
do
letter=$(printf '%#x' $i | sed -e 's/0x//g')
echo $letter
done