rclone/cmd/cat/cat.go
Nick Craig-Wood bff702a6f1 docs: group the global flags and make them appear on command and flags pages
This adds an additional parameter to the creation of each flag. This
specifies one or more flag groups. This **must** be set for global
flags and **must not** be set for local flags.

This causes flags.md to be built with sections to aid comprehension
and it causes the documentation pages for each command (and the
`--help`) to be built showing the flags groups as specified in the
`groups` annotation on the command.

See: https://forum.rclone.org/t/make-docs-for-mortals-not-only-rclone-gurus/39476/
2023-08-02 12:53:09 +01:00

103 lines
3 KiB
Go

// Package cat provides the cat command.
package cat
import (
"context"
"io"
"log"
"os"
"strings"
"github.com/rclone/rclone/cmd"
"github.com/rclone/rclone/fs/config/flags"
"github.com/rclone/rclone/fs/operations"
"github.com/spf13/cobra"
)
// Globals
var (
head = int64(0)
tail = int64(0)
offset = int64(0)
count = int64(-1)
discard = false
separator = string("")
)
func init() {
cmd.Root.AddCommand(commandDefinition)
cmdFlags := commandDefinition.Flags()
flags.Int64VarP(cmdFlags, &head, "head", "", head, "Only print the first N characters", "")
flags.Int64VarP(cmdFlags, &tail, "tail", "", tail, "Only print the last N characters", "")
flags.Int64VarP(cmdFlags, &offset, "offset", "", offset, "Start printing at offset N (or from end if -ve)", "")
flags.Int64VarP(cmdFlags, &count, "count", "", count, "Only print N characters", "")
flags.BoolVarP(cmdFlags, &discard, "discard", "", discard, "Discard the output instead of printing", "")
flags.StringVarP(cmdFlags, &separator, "separator", "", separator, "Separator to use between objects when printing multiple files", "")
}
var commandDefinition = &cobra.Command{
Use: "cat remote:path",
Short: `Concatenates any files and sends them to stdout.`,
// Warning! "|" will be replaced by backticks below
Long: strings.ReplaceAll(`
rclone cat sends any files to standard output.
You can use it like this to output a single file
rclone cat remote:path/to/file
Or like this to output any file in dir or its subdirectories.
rclone cat remote:path/to/dir
Or like this to output any .txt files in dir or its subdirectories.
rclone --include "*.txt" cat remote:path/to/dir
Use the |--head| flag to print characters only at the start, |--tail| for
the end and |--offset| and |--count| to print a section in the middle.
Note that if offset is negative it will count from the end, so
|--offset -1 --count 1| is equivalent to |--tail 1|.
Use the |--separator| flag to print a separator value between files. Be sure to
shell-escape special characters. For example, to print a newline between
files, use:
* bash:
rclone --include "*.txt" --separator $'\n' cat remote:path/to/dir
* powershell:
rclone --include "*.txt" --separator "|n" cat remote:path/to/dir
`, "|", "`"),
Annotations: map[string]string{
"versionIntroduced": "v1.33",
"groups": "Filter,Listing",
},
Run: func(command *cobra.Command, args []string) {
usedOffset := offset != 0 || count >= 0
usedHead := head > 0
usedTail := tail > 0
if usedHead && usedTail || usedHead && usedOffset || usedTail && usedOffset {
log.Fatalf("Can only use one of --head, --tail or --offset with --count")
}
if head > 0 {
offset = 0
count = head
}
if tail > 0 {
offset = -tail
count = -1
}
cmd.CheckArgs(1, 1, command, args)
fsrc := cmd.NewFsSrc(args)
var w io.Writer = os.Stdout
if discard {
w = io.Discard
}
cmd.Run(false, false, command, func() error {
return operations.Cat(context.Background(), fsrc, w, offset, count, []byte(separator))
})
},
}