---
name: "svscan"
section: "8"
platform: "linux"
package: "daemontools"
version: "1:0.76-14"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/svscan"
---

# svscan(8)

starts and monitors a collection of services

## NAME

svscan - starts and monitors a collection of services

## SYNOPSIS

**svscan** \[ *directory* \]

## DESCRIPTION

**svscan** starts one [**supervise**(8)](/supervise/8.md) process for each subdirectory of the current directory, up to a limit of 1000 subdirectories. **svscan** skips subdirectory names starting with dots. [**supervise**(8)](/supervise/8.md) must be in **svscan**'s path.

**svscan** optionally starts a pair of [**supervise**(8)](/supervise/8.md) processes, one for a subdirectory *s*, one for *s/**log***, with a pipe between them. It does this if the name *s* is at most 255 bytes long and *s/**log*** exists. (In versions 0.70 and below, it does this if *s* is sticky.) **svscan** needs two free descriptors for each pipe.

Every five seconds, **svscan** checks for subdirectories again. If it sees a new subdirectory, it starts a new [**supervise**(8)](/supervise/8.md) process. If it sees an old subdirectory where a [**supervise**(8)](/supervise/8.md) process has exited, it restarts the [**supervise**(8)](/supervise/8.md) process. In the **log** case it reuses the same pipe so that no data is lost.

**svscan** is designed to run forever. If it has trouble creating a pipe or running [**supervise**(8)](/supervise/8.md), it prints a message to stderr; it will try again five seconds later.

If **svscan** is given a command-line argument *directory*, it switches to that *directory* when it starts.

## SEE ALSO

[supervise(8)](/supervise/8.md), [svc(8)](/svc/8.md), [svok(8)](/svok/8.md), [svstat(8)](/svstat/8.md), [svscanboot(8)](/svscanboot/8.md), [readproctitle(8)](/readproctitle/8.md), [fghack(8)](/fghack/8.md),   [pgrphack(8)](/pgrphack/8.md), [multilog(8)](/multilog/8.md), [tai64n(8)](/tai64n/8.md), [tai64nlocal(8)](/tai64nlocal/8.md), [setuidgid(8)](/setuidgid/8.md), [envuidgid(8)](/envuidgid/8.md), [envdir(8)](/envdir/8.md), [softlimit(8)](/softlimit/8.md), [setlock(8)](/setlock/8.md)

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