Changing TIME_FORMAT to \pset time <FORMAT>

Changes the way the time display value is set. Deviates from `psql` as
`psql` has no client side setting for changing time display.

README.md

@@ -859,31 +859,54 @@ highlighting:
 
 Some databases support time/date columns that [support formatting][go-time]. By
 default, `usql` formats time/date columns as [RFC3339Nano][go-time], and can be
-set using the [`TIME_FORMAT` variable][variables]:
+set using `\pset time <FORMAT>`:
 
 ```sh
 $ usql pg://
-Connected with driver postgres (PostgreSQL 9.6.9)
+Connected with driver postgres (PostgreSQL 13.2 (Debian 13.2-1.pgdg100+1))
 Type "help" for help.
 
-pg:booktest@=> \set
-TIME_FORMAT = 'RFC3339Nano'
-pg:booktest@=> select now();
-                now
-+----------------------------------+
-  2018-06-14T03:24:12.481923+07:00
-(1 rows)
-
-pg:booktest@=> \set TIME_FORMAT Kitchen
-pg:booktest@=> \g
+pg:postgres@=> \pset
+time                     RFC3339Nano
+pg:postgres@=> select now();
+             now
+-----------------------------
+ 2021-05-01T22:21:44.710385Z
+(1 row)
+
+pg:postgres@=> \pset time Kitchen
+Time display is "Kitchen" ("3:04PM").
+pg:postgres@=> select now();
    now
-+--------+
-  3:24AM
-(1 rows)
+---------
+ 10:22PM
+(1 row)
+
+pg:postgres@=>
 ```
 
-Any [Go supported time format][go-time] or const name (for example, `Kitchen`,
-in the above) can be used for `TIME_FORMAT`.
+Any [Go supported time format][go-time] or the standard Go const name (for example,
+`Kitchen`, in the above).
+
+##### Constants
+
+| Constant Name | Value                                 |
+|---------------|---------------------------------------|
+| ANSIC         | `Mon Jan _2 15:04:05 2006`            |
+| UnixDate      | `Mon Jan _2 15:04:05 MST 2006`        |
+| RubyDate      | `Mon Jan 02 15:04:05 -0700 2006`      |
+| RFC822        | `02 Jan 06 15:04 MST`                 |
+| RFC822Z       | `02 Jan 06 15:04 -0700`               |
+| RFC850        | `Monday, 02-Jan-06 15:04:05 MST`      |
+| RFC1123       | `Mon, 02 Jan 2006 15:04:05 MST`       |
+| RFC1123Z      | `Mon, 02 Jan 2006 15:04:05 -0700`     |
+| RFC3339       | `2006-01-02T15:04:05Z07:00`           |
+| RFC3339Nano   | `2006-01-02T15:04:05.999999999Z07:00` |
+| Kitchen       | `3:04PM`                              |
+| Stamp         | `Jan _2 15:04:05`                     |
+| StampMilli    | `Jan _2 15:04:05.000`                 |
+| StampMicro    | `Jan _2 15:04:05.000000`              |
+| StampNano     | `Jan _2 15:04:05.000000000`           |
 
 #### Copy
 

env/types.go

@@ -40,10 +40,6 @@ func init() {
 	if v := Getenv("USQL_SHOW_HOST_INFORMATION"); v != "" {
 		enableHostInformation = v
 	}
-	timefmt := "RFC3339Nano"
-	if v := Getenv("USQL_TIME_FORMAT"); v != "" {
-		timefmt = v
-	}
 	// get color level
 	colorLevel, _ := terminfo.ColorLevelFromEnv()
 	enableSyntaxHL := "true"
@@ -53,7 +49,6 @@ func init() {
 	vars = Vars{
 		// usql related logic
 		"SHOW_HOST_INFORMATION": enableHostInformation,
-		"TIME_FORMAT":           timefmt,
 		"PAGER":                 Getenv("USQL_PAGER", "PAGER"),
 		// syntax highlighting variables
 		"SYNTAX_HL":             enableSyntaxHL,
@@ -78,6 +73,7 @@ func init() {
 		"recordsep":                "\n",
 		"recordsep_zero":           "off",
 		"tableattr":                "",
+		"time":                     "RFC3339Nano",
 		"title":                    "",
 		"tuples_only":              "off",
 		"unicode_border_linestyle": "single",
@@ -262,7 +258,7 @@ func Ptoggle(name, extra string) (string, error) {
 			pvars[name] = "aligned"
 		}
 	case "linestyle":
-	case "csv_fieldsep", "fieldsep", "null", "recordsep":
+	case "csv_fieldsep", "fieldsep", "null", "recordsep", "time":
 	case "tableattr", "title":
 		pvars[name] = ""
 	case "unicode_border_linestyle", "unicode_column_linestyle", "unicode_header_linestyle":
@@ -310,7 +306,7 @@ func Pset(name, value string) (string, error) {
 			return "", text.ErrInvalidFormatLineStyle
 		}
 		pvars[name] = value
-	case "csv_fieldsep", "fieldsep", "null", "recordsep", "tableattr", "title":
+	case "csv_fieldsep", "fieldsep", "null", "recordsep", "tableattr", "time", "title":
 		pvars[name] = value
 	case "unicode_border_linestyle", "unicode_column_linestyle", "unicode_header_linestyle":
 		if !borderRE.MatchString(value) {
@@ -342,9 +338,9 @@ var timeConstMap = map[string]string{
 	"StampNano":   time.StampNano,
 }
 
-// Timefmt returns the environment TIME_FORMAT.
-func Timefmt() string {
-	tfmt := vars["TIME_FORMAT"]
+// GoTime returns the user's time format converted to Go's time.Format value.
+func GoTime() string {
+	tfmt := pvars["time"]
 	if s, ok := timeConstMap[tfmt]; ok {
 		return s
 	}

go.mod

@@ -80,7 +80,7 @@ require (
 	github.com/vertica/vertica-sql-go v1.1.1
 	github.com/vmihailenco/msgpack/v5 v5.3.1 // indirect
 	github.com/xo/dburl v0.6.1
-	github.com/xo/tblfmt v0.7.3
+	github.com/xo/tblfmt v0.7.4
 	github.com/xo/terminfo v0.0.0-20210125001918-ca9a967f8778
 	github.com/zaf/temp v0.0.0-20170209143821-94e385923345
 	github.com/ziutek/mymysql v1.5.4

go.sum

@@ -1071,8 +1071,8 @@ github.com/xinsnake/go-http-digest-auth-client v0.6.0/go.mod h1:QK1t1v7ylyGb363v
 github.com/xo/dburl v0.6.1 h1:Y2lQsjXbAbBy0RZjsLAefS0Hu7DxOizHMN/iGcoXN9U=
 github.com/xo/dburl v0.6.1/go.mod h1:W68zXnBfTb4zcKLI1yEYRyYIQjcjoyCRn4YMD/QzcpE=
 github.com/xo/tblfmt v0.0.0-20190609041254-28c54ec42ce8/go.mod h1:3U5kKQdIhwACye7ml3acccHmjGExY9WmUGU7rnDWgv0=
-github.com/xo/tblfmt v0.7.3 h1:KBYR7jumA1uxO7kQ6f6Gzmh4gSvKC+drYOfao1U2JFs=
-github.com/xo/tblfmt v0.7.3/go.mod h1:2fh9mXteiVnG68zzU2TS+CsCCU9lq3mgLi/EYw7ljrM=
+github.com/xo/tblfmt v0.7.4 h1:i8kyQFBVVqLkl6T4nX76axFNCSYf2w5ARsCScryPU0Q=
+github.com/xo/tblfmt v0.7.4/go.mod h1:2fh9mXteiVnG68zzU2TS+CsCCU9lq3mgLi/EYw7ljrM=
 github.com/xo/terminfo v0.0.0-20210125001918-ca9a967f8778 h1:QldyIu/L63oPpyvQmHgvgickp1Yw510KJOqX7H24mg8=
 github.com/xo/terminfo v0.0.0-20210125001918-ca9a967f8778/go.mod h1:2MuV+tbUrU1zIOPMxZ5EncGwgmMJsa+9ucAQZXxsObs=
 github.com/xwb1989/sqlparser v0.0.0-20180606152119-120387863bf2 h1:zzrxE1FKn5ryBNl9eKOeqQ58Y/Qpo3Q9QNxKHX5uzzQ=

handler/handler.go

@@ -805,15 +805,6 @@ func (h *Handler) Print(format string, a ...interface{}) {
 	fmt.Fprintln(out)
 }
 
-// timefmt returns the current time format setting.
-func (h *Handler) timefmt() string {
-	s := env.Timefmt()
-	if s == "" {
-		s = time.RFC3339Nano
-	}
-	return s
-}
-
 // execWatch repeatedly executes a query against the database.
 func (h *Handler) execWatch(ctx context.Context, w io.Writer, opt metacmd.Option, prefix, qstr string, qtyp bool) error {
 	for {
@@ -860,7 +851,7 @@ func (h *Handler) execSet(ctx context.Context, w io.Writer, opt metacmd.Option,
 	// process row(s)
 	var i int
 	var row []string
-	clen, tfmt := len(cols), h.timefmt()
+	clen, tfmt := len(cols), env.GoTime()
 	for q.Next() {
 		if i == 0 {
 			row, err = h.scan(q, clen, tfmt)
@@ -917,7 +908,7 @@ func (h *Handler) query(ctx context.Context, w io.Writer, opt metacmd.Option, _,
 	}
 	defer q.Close()
 	params := env.Pall()
-	params["time_format"] = env.Timefmt()
+	params["time"] = env.GoTime()
 	for k, v := range opt.Params {
 		params[k] = v
 	}
@@ -983,7 +974,7 @@ func (h *Handler) execRows(ctx context.Context, w io.Writer, q *sql.Rows) error
 	}
 	// process rows
 	res := metacmd.Option{Exec: metacmd.ExecOnly}
-	clen, tfmt := len(cols), h.timefmt()
+	clen, tfmt := len(cols), env.GoTime()
 	for q.Next() {
 		if clen != 0 {
 			row, err := h.scan(q, clen, tfmt)

metacmd/cmds.go

@@ -708,6 +708,12 @@ func init() {
 				case !strings.Contains(mask, "%"):
 					p.Handler.Print(mask)
 				default:
+					if field == "time" {
+						val = fmt.Sprintf("%q", val)
+						if tfmt := env.GoTime(); tfmt != val {
+							val = fmt.Sprintf("%s (%q)", val, tfmt)
+						}
+					}
 					p.Handler.Print(mask, val)
 				}
 				return nil

text/text.go

@@ -71,6 +71,7 @@ var (
 		`recordsep`:                `Field separator is %q.`,
 		`recordsep_zero`:           `Record separator is zero byte.`,
 		`tableattr`:                `Table attributes are %q.`,
+		`time`:                     `Time display is %s.`,
 		`title`:                    `Title is %q.`,
 		`tuples_only`:              `Tuples only is %s.`,
 		`unicode_border_linestyle`: `Unicode border line style is %q.`,