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- package system
- import (
- "io/ioutil"
- "path/filepath"
- "strconv"
- "strings"
- )
- // look in /proc to find the process start time so that we can verify
- // that this pid has started after ourself
- func GetProcessStartTime(pid int) (string, error) {
- data, err := ioutil.ReadFile(filepath.Join("/proc", strconv.Itoa(pid), "stat"))
- if err != nil {
- return "", err
- }
- return parseStartTime(string(data))
- }
- func parseStartTime(stat string) (string, error) {
- // the starttime is located at pos 22
- // from the man page
- //
- // starttime %llu (was %lu before Linux 2.6)
- // (22) The time the process started after system boot. In kernels before Linux 2.6, this
- // value was expressed in jiffies. Since Linux 2.6, the value is expressed in clock ticks
- // (divide by sysconf(_SC_CLK_TCK)).
- //
- // NOTE:
- // pos 2 could contain space and is inside `(` and `)`:
- // (2) comm %s
- // The filename of the executable, in parentheses.
- // This is visible whether or not the executable is
- // swapped out.
- //
- // the following is an example:
- // 89653 (gunicorn: maste) S 89630 89653 89653 0 -1 4194560 29689 28896 0 3 146 32 76 19 20 0 1 0 2971844 52965376 3920 18446744073709551615 1 1 0 0 0 0 0 16781312 137447943 0 0 0 17 1 0 0 0 0 0 0 0 0 0 0 0 0 0
- // get parts after last `)`:
- s := strings.Split(stat, ")")
- parts := strings.Split(strings.TrimSpace(s[len(s)-1]), " ")
- return parts[22-3], nil // starts at 3 (after the filename pos `2`)
- }
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