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  PING			FreeBSD	System Manager's Manual		 PING

       NAME    
    

    ping    
 -- send ICMP or ICMPv6 ECHO_REQUEST packets to network hosts

       SYNOPSIS    
    

    ping    
 [    -4AaDdfHnoQqRrv    
] [    -.      
    chars    
] [    -C    
    pcp    
] [    -c    
    count    
] [    -G    
    sweepmaxsize    
]
	 [    -g    
    sweepminsize    
] [    -h    
	    sweepincrsize    
] [    -i    
    wait    
] [    -l    
    preload    
]
	 [    -M    
    mask    
 |    time    
] [    -m    
    ttl    
] [    -P    
	    policy    
]	[    -p    
    pattern    
] [    -S    
    src    
_    addr    
]
	 [    -s    
    packetsize    
] [    -t    
    timeout    
] [    -W    
    waittime    
] [    -z    
    tos    
]    IPv4-host    

    ping    
 [    -4AaDdfHLnoQqRrv    
] [    -.      
    chars    
] [    -C    
    pcp    
]	[    -c    
    count    
] [    -I    
    iface    
]
	 [    -i    
    wait    
] [    -l    
	    preload    
] [    -M    
    mask    
 |    time    
] [    -m    
    ttl    
] [    -P    
    policy    
]
	 [    -p    
    pattern    
] [    -S    
    src    
_    addr    
] [    -s    
    packetsize    
] [    -T    
    ttl    
] [    -t    
    timeout    
]
	 [    -W    
    waittime    
]	[    -z    
    tos    
]    IPv4-mcast-group    

    ping    
 [    -6AaDdEfHNnOoquvYyZ    
]	[    -.      
    chars    
] [    -b    
    bufsiz    
] [    -c    
    count    
] [    -e    
    gateway    
]
	 [    -I    
    interface    
] [    -i    
    wait    
] [    -k    
    addrtype    
] [    -l    
    preload    
] [    -m    
    hoplimit    
]
	 [    -P    
    policy    
] [    -p    
    pattern    
] [    -S    
    sourceaddr    
] [    -s    
    packetsize    
]
	 [    -t    
    timeout    
] [    -W    
    waittime    
] [    IPv6-hops    
	    .      
]    IPv6-host    


       DESCRIPTION    
    

 The    ping    
 utility invoked with an IPv4 target (    IPv4-host    
 or
    IPv4-mcast-group    
) uses the	ICMP protocol's	mandatory ECHO_REQUEST data-
 gram to elicit an ICMP ECHO_RESPONSE from a host or gateway.    ECHO_RE-
 QUEST datagrams ("pings") have an IP and ICMP header, followed by a
 "struct timeval" and then an arbitrary number of "pad" bytes used to fill
 out the packet.

 When invoked with an IPv6 target (    IPv6-host    
), it uses the ICMPv6 proto-
 col's mandatory ICMP6_ECHO_REQUEST	datagram to elicit an ICMP6_ECHO_RE-
 PLY.    ICMP6_ECHO_REQUEST datagrams	have an	IPv6 header and	ICMPv6 header
 formatted as documented in	RFC 2463.

 When invoked with a hostname, the version to which	the target is resolved
 first is used.    In	that case, the options and arguments used must be
 valid for the specific IP version,	otherwise    ping    
 exits with an error.
 If	the target is resolved to both IPv4 and	IPv6, the specific IP version
 can be requested by    -4    
 or    -6    
 options, respectively.    For backwards-com-
 patibility, ICMPv6	can also be selected by	invoking the binary as    ping6    
.

    Options    
    common    
    to    
    both    
    IPv4    
    and    
    IPv6    
	    targets    

    -.      
    chars    

	 By	default, for every ECHO_REQUEST	sent, a	period "." is printed,
	 while for every ECHO_REPLY	received, a backspace is printed.
	 This option takes an optional string argument listing characters
	 that will be printed one by one in	the provided order instead of
	 the default period.

	 Example usage:

		 ping	-.0123456789 freebsd.org

    -A    
	 Audible.    Output a	bell (ASCII 0x07) character when no packet is
	 received before the next packet is	transmitted.    To cater for
	 round-trip	times that are longer than the interval	between	trans-
	 missions, further missing packets cause a bell only if the	maxi-
	 mum number	of unreceived packets has increased.

    -a    
	 Audible.    Include a bell (ASCII 0x07) character in	the output
	 when any packet is	received.

    -C    
	    pcp    
 Add an 802.1p Ethernet Priority Code Point	when sending a packet.
	 0.7 uses that specific PCP, -1 uses the interface	default	PCP
	 (or none).

    -c    
	    count    

	 Stop after	sending	(and receiving)	    count    
 ECHO_RESPONSE packets.
	 If	this option is not specified,    ping    
 will	operate	until inter-
	 rupted.

	 For an IPv4 target, if this option	is specified in	conjunction
	 with ping sweeps, each sweep will consist of    count    
	packets.

    -D    
	 Disable fragmentation.

    -d    
	 Set the SO_DEBUG option on	the socket being used.

    -f    
	 Flood ping.    Outputs packets as fast as they come back or one
	 hundred times per second, whichever is more.    Implies    -.      
 to print
	 a period for every	ECHO_REQUEST sent and a	backspace for every
	 ECHO_REPLY	received.    This	provides a rapid display of how	many
	 packets are being dropped.	 Only the super-user may use this op-
	 tion.      This    
    can    
    be    
	    very    
    hard    
    on    
    a    
    network    
    and    
    should    
    be    
    used    
    with    

	    caution.      


    -H    
	 Hostname output.    Try to do a reverse DNS lookup when displaying
	 addresses.	 This is the opposite of the    -n    
	option.

    -I    
	    iface    

	 For an IPv4 target,    iface    
 is an IP	address	indentifying an	inter-
	 face from which the packets will be sent.	This flag applies only
	 if	the ping target	is a multicast address.

	 For an IPv6 target,    iface    
 is a name of an interface (e.g.,	`em0')
	 from which	the packets will be sent.    This	flag applies if	the
	 ping target is a multicast	address, or link-local/site-local uni-
	 cast address.

    -i    
	    wait    

	 Wait    wait    
 seconds    between    
    sending    
    each    
    packet    
.    The default is to
	 wait for one second between each packet.    The wait	time may be
	 fractional, but only the super-user may specify values less than
	 1 second.	This option is incompatible with the    -f    
	option.

    -l    
	    preload    

	 If	    preload    
	is specified,    ping    
 sends that many packets as fast as
	 possible before falling into its normal mode of behavior.	Only
	 the super-user may	use this option.

    -m    
	    ttl    
 For an IPv4 target, set the IP Time To Live for outgoing packets.
	 If	not specified, the kernel uses the value of the
	    net.inet.ip.ttl    
 MIB variable.

	 For an IPv6 target, set the IPv6 hoplimit.

    -n    
	 Numeric output only.    No attempt will be made to lookup symbolic
	 names for host addresses.	This is	the opposite of	    -H    
, and	it is
	 the default behavior.

    -o    
	 Exit successfully after receiving one reply packet.

    -P    
	    policy    

	    policy    
 specifies IPsec policy for the ping	session.    For details
	 please refer to    ipsec    
 and    ipsec_set_policy    
.

    -p    
	    pattern    

	 You may specify up	to 16 "pad" bytes to fill out the packet you
	 send.    This is useful for diagnosing data-dependent problems in a
	 network.    For example, "-p	ff" will cause the sent	packet to be
	 filled with all ones.

    -q    
	 Quiet output.    Nothing is displayed except	the summary lines at
	 startup time and when finished.

    -S    
	    src    
_    addr    

	 Use the following IP address as the source	address	in outgoing
	 packets.    On hosts	with more than one IP address, this option can
	 be	used to	force the source address to be something other than
	 the IP address of the interface the probe packet is sent on.

	 For IPv4, if the IP address is not	one of this machine's inter-
	 face addresses, an	error is returned and nothing is sent.

	 For IPv6, the source address must be one of the unicast addresses
	 of	the sending node, and must be numeric.

    -s    
	    packetsize    

	 Specify the number	of data	bytes to be sent.    The default is 56,
	 which translates into 64 ICMP data	bytes when combined with the 8
	 bytes of ICMP header data.

	 For IPv4, only the	super-user may specify values more than	de-
	 fault.    This option cannot	be used	with ping sweeps.

	 For IPv6, you may need to specify    -b    
 as well to extend socket
	 buffer size.

    -t    
	    timeout    

	 Specify a timeout,	in seconds, before ping	exits regardless of
	 how many packets have been	received.

    -v    
	 Verbose output.    ICMP packets other than ECHO_RESPONSE that are
	 received are listed.

    -W    
	    waittime    

	 Time in milliseconds to wait for a	reply for each packet sent.
	 If	a reply	arrives	later, the packet is not printed as replied,
	 but considered as replied when calculating	statistics.

    Options    
    only    
	    for    
    IPv4    
    targets    

    -4    
	 Use IPv4 regardless of how	the target is resolved.

    -G    
	    sweepmaxsize    

	 Specify the maximum size of ICMP payload when sending sweeping
	 pings.    This option is required for ping sweeps.

    -g    
	    sweepminsize    

	 Specify the size of ICMP payload to start with when sending
	 sweeping pings.    The default value	is 0.

    -h    
	    sweepincrsize    

	 Specify the number	of bytes to increment the size of ICMP payload
	 after each	sweep when sending sweeping pings.    The	default	value
	 is	1.

    -L    
	 Suppress loopback of multicast packets.    This flag	only applies
	 if	the ping destination is	a multicast address.

    -M    
	    mask    
 |    time    

	 Use ICMP_MASKREQ or ICMP_TSTAMP instead of	ICMP_ECHO.    For	    mask    
,
	 print the netmask of the remote machine.    Set the
	    net.inet.icmp.maskrepl    
 MIB	variable to enable ICMP_MASKREPLY and
	    net.inet.icmp.maskfake    
 if you want	to override the	netmask	in the
	 response.	For    time    
, print	the origination, reception and trans-
	 mission timestamps.    Set the    net.inet.icmp.tstamprepl    
 MIB vari-
	 able to enable or disable ICMP_TSTAMPREPLY.

    -Q    
	 Somewhat quiet output.    Don't display ICMP	error messages that
	 are in response to	our query messages.    Originally, the    -v    
	flag
	 was required to display such errors, but    -v    
 displays all ICMP er-
	 ror messages.    On a busy machine, this output can be overbearing.
	 Without the    -Q    
 flag,    ping    
 prints out any ICMP error messages
	 caused by its own ECHO_REQUEST messages.

    -R    
	 Record route.    Includes the RECORD_ROUTE option in	the ECHO_RE-
	 QUEST packet and displays the route buffer	on returned packets.
	 Note that the IP header is	only large enough for nine such
	 routes; the    traceroute    
 command is usually better at determin-
	 ing the route packets take	to a particular	destination.    If more
	 routes come back than should, such	as due to an illegal spoofed
	 packet, ping will print the route list and	then truncate it at
	 the correct spot.	Many hosts ignore or discard the RECORD_ROUTE
	 option.

    -r    
	 Bypass the	normal routing tables and send directly	to a host on
	 an	attached network.    If the host is not on a directly-attached
	 network, an error is returned.    This option can be	used to	ping a
	 local host	through	an interface that has no route through it
	 (e.g., after the interface	was dropped by    routed    
).

    -T    
	    ttl    
 Set the IP	Time To	Live for multicasted packets.    This flag only
	 applies if	the ping destination is	a multicast address.

    -z    
	    tos    
 Use the specified type of service.

    IPv4-host    

	 hostname or IPv4 address of the final destination node.

    IPv4-mcast-group    

	 IPv4 multicast address of the final destination nodes.

    Options    
    only    
	    for    
    IPv6    
    targets    

    -6    
	 Use IPv6 regardless of how	the target is resolved.

    -b    
	    bufsiz    

	 Set socket	buffer size.

    -e    
	    gateway    

	 Specifies to use    gateway    
 as the next hop to the destination.    The
	 gateway must be a neighbor	of the sending node.

    -k    
	    addrtype    

	 Generate ICMPv6 Node Information Node Addresses query, rather
	 than echo-request.	    addrtype    
 must be a string constructed of the
	 following characters.
	    a    
	 requests unicast addresses	from all of the	responder's
		 interfaces.    If the character is omitted, only those ad-
		 dresses which belong to the interface which has the re-
		 sponder's address are requests.
	    c    
	 requests responder's IPv4-compatible and IPv4-mapped ad-
		 dresses.
	    g    
	 requests responder's global-scope addresses.
	    s    
	 requests responder's site-local addresses.
	    l    
	 requests responder's link-local addresses.
	    A    
	 requests responder's anycast addresses.    Without this
		 character,	the responder will return unicast addresses
		 only.    With this character, the responder will return
		 anycast addresses only.    Note that	the specification does
		 not specify how to	get responder's	anycast	addresses.
		 This is an	experimental option.

    -N    
	 Probe node	information multicast group address
	 (ff02::2:ffxx:xxxx).      host    
	must be	string hostname	of the target
	 (must not be a numeric IPv6 address).    Node information multicast
	 group will	be computed based on given    host    
, and will be used as
	 the final destination.    Since node	information multicast group is
	 a link-local multicast group, outgoing interface needs to be
	 specified by    -I    
 option.

	 When specified twice, the address (ff02::2:xxxx:xxxx) is used in-
	 stead.    The former	is in RFC 4620,	the latter is in an old	Inter-
	 net Draft draft-ietf-ipngwg-icmp-name-lookup.    Note that KAME-de-
	 rived implementations including FreeBSD use the latter.

    -O    
	 Generate ICMPv6 Node Information supported	query types query,
	 rather than echo-request.	    -s    
 has no effect if    -O    
 is specified.

    -u    
	 By	default,    ping    
 asks the kernel to fragment packets to fit into
	 the minimum IPv6 MTU.    The	    -u    
 option will suppress	the behavior
	 in	the following two levels: when the option is specified once,
	 the behavior will be disabled for unicast packets.	 When the op-
	 tion is more than once, it	will be	disabled for both unicast and
	 multicast packets.

    -Y    
	 Same as    -y    
, but with old packet format based on 03	draft.	This
	 option is present for backward compatibility.      -s    
 has no effect
	 if	    -y    
 is specified.

    -y    
	 Generate ICMPv6 Node Information DNS Name query, rather than
	 echo-request.      -s    
 has no effect if	    -y    
 is specified.

    IPv6-hops    

	 IPv6 addresses for	intermediate nodes, which will be put into
	 type 0 routing header.

    IPv6-host    

	 IPv6 address of the final destination node.

    Experimental    
	    options    
	    only    
    for    
    IPv6    
    target    

    -E    
	 Enables transport-mode IPsec encapsulated security	payload.

    -Z    
	 Enables transport-mode IPsec authentication header.

 When using	    ping    
 for fault isolation, it should first be run on the	local
 host, to verify that the local network interface is up and	running.
 Then, hosts and gateways further and further away should be "pinged".
 Round-trip	times and packet loss statistics are computed.	If duplicate
 packets are received, they	are not	included in the	packet loss calcula-
 tion, although the	round trip time	of these packets is used in calculat-
 ing the round-trip	time statistics.    When the specified number of packets
 have been sent (and received) or if the program is	terminated with	a
 SIGINT, a brief summary is	displayed, showing the number of packets sent
 and received, and the minimum, mean, maximum, and standard	deviation of
 the round-trip times.

 If	    ping    
 receives a	SIGINFO	(see the    status    
	argument for    stty    
) signal,
 the current number	of packets sent	and received, and the minimum, mean,
 maximum, and standard deviation of	the round-trip times will be written
 to	the standard output.

 This program is intended for use in network testing, measurement and man-
 agement.    Because of the load it can impose on the	network, it is unwise
 to	use    ping    
 during	normal operations or from automated scripts.

       ICMP PACKET DETAILS    
    

 An	IP header without options is 20	bytes.	An ICMP	ECHO_REQUEST packet
 contains an additional 8 bytes worth of ICMP header followed by an	arbi-
 trary amount of data.    When a    packetsize    
 is given,	this indicated the
 size of this extra	piece of data (the default is 56).    Thus the amount of
 data received inside of an	IP packet of type ICMP ECHO_REPLY will always
 be	8 bytes	more than the requested	data space (the	ICMP header).

 If	the data space is at least eight bytes large,    ping    
 uses	the first
 eight bytes of this space to include a timestamp which it uses in the
 computation of round trip times.    If less than eight bytes	of pad are
 specified,	no round trip times are	given.

       DUPLICATE AND DAMAGED PACKETS    
    

 The    ping    
 utility will report duplicate and	damaged	packets.    Duplicate
 packets should never occur	when pinging a unicast address,	and seem to be
 caused by inappropriate link-level	retransmissions.    Duplicates may occur
 in	many situations	and are	rarely (if ever) a good	sign, although the
 presence of low levels of duplicates may not always be cause for alarm.
 Duplicates	are expected when pinging a broadcast or multicast address,
 since they	are not	really duplicates but replies from different hosts to
 the same request.

 Damaged packets are obviously serious cause for alarm and often indicate
 broken hardware somewhere in the    ping    
 packet's path (in the network or in
 the hosts).

       TRYING DIFFERENT DATA PATTERNS    
    

 The (inter)network	layer should never treat packets differently depending
 on	the data contained in the data portion.	 Unfortunately,	data-dependent
 problems have been	known to sneak into networks and remain	undetected for
 long periods of time.    In many cases the particular pattern that will
 have problems is something	that does not have sufficient "transitions",
 such as all ones or all zeros, or a pattern right at the edge, such as
 almost all	zeros.	It is not necessarily enough to	specify	a data pattern
 of	all zeros (for example)	on the command line because the	pattern	that
 is	of interest is at the data link	level, and the relationship between
 what you type and what the	controllers transmit can be complicated.

 This means	that if	you have a data-dependent problem you will probably
 have to do	a lot of testing to find it.    If you are lucky,	you may	manage
 to	find a file that either	cannot be sent across your network or that
 takes much	longer to transfer than	other similar length files.    You can
 then examine this file for	repeated patterns that you can test using the
    -p    
	option of    ping    
.

       IPv4 TTL DETAILS    
    

 The TTL value of an IP packet represents the maximum number of IP routers
 that the packet can go through before being thrown	away.    In current
 practice you can expect each router in the	Internet to decrement the TTL
 field by exactly one.

 The TCP/IP	specification recommends setting the TTL field for IP packets
 to	64.

 The maximum possible value	of this	field is 255, and some UNIX systems
 set the TTL field of ICMP ECHO_REQUEST packets to 255.    This is why you
 will find you can "ping" some hosts, but not reach	them with    telnet    
 or
    ftp    
.

 In	normal operation    ping    
 prints the ttl value from	the packet it re-
 ceives.    When a remote system receives a ping packet, it can do one of
 three things with the TTL field in	its response:

    o    
	 Not change it;	this is	what BSD systems did before the	4.3BSD-Tahoe
	 release.    In this case	the TTL	value in the received packet will be
	 255 minus the number of routers in the	round-trip path.

    o    
	 Set it	to 64; this is what current FreeBSD systems do.	 In this case
	 the TTL value in the received packet will be 64 minus the number of
	 routers in the	path    from    
 the remote system    to    
 the    ping    
    ing    
 host.

    o    
	 Set it	to some	other value.    Some machines use	the same value for
	 ICMP packets that they	use for	TCP packets, for example either	30 or
	 60.    Others may use completely	wild values.

       EXIT STATUS    
    

 The    ping    
 utility exits with one of	the following values:

 0	 At	least one response was heard from the specified	    host    
.

 2	 The transmission was successful but no responses were received.

 any other value
	 An	error occurred.

       EXAMPLES    
    

 The following will	send ICMPv6 echo request to dst.example.com.

	 ping	-6 -n dst.example.com

 The following will	probe hostnames	for all	nodes on the network link at-
 tached to wi0 interface.    The address ff02::1 is named the	link-local
 all-node multicast	address, and the packet	would reach every node on the
 network link.

	 ping	-6 -y ff02::1%wi0

 The following will	probe addresses	assigned to the	destination node,
 dst.example.com.

	 ping	-6 -k agl dst.example.com

       SEE ALSO    
    

    netstat    
,    icmp    
,    icmp6    
,    inet6    
,    ip6    
,    ifconfig    
,    routed    
,
    traceroute    
,    traceroute6    


 A.	Conta and S.  Deering,    Internet    
    Control    
    Message    
    Protocol    
	    (ICMPv6)    
    for    

    the    
    Internet    
    Protocol    
    Version    
    6    
    (IPv6)    
    Specification    
, RFC 2463, December
 1998.

 Matt Crawford,    IPv6    
    Node    
    Information    
    Queries    
, draft-ietf-ipngwg-icmp-
 name-lookups-09.txt, May 2002, work in progress material.

       HISTORY    
    

 The    ping    
 utility appeared in 4.3BSD.    The    ping6    
 utility with IPv6 support
 first appeared in the WIDE	Hydrangea IPv6 protocol	stack kit.

 IPv6 and IPsec support based on the KAME Project (       http://www.kame.net/    
    
)
 stack was initially integrated into FreeBSD 4.0.

 The    ping6    
 utility was merged to    ping    
 in Google Summer of Code 2019.

       AUTHORS    
    

 The original    ping    
 utility was written by Mike Muuss while at the US Army
 Ballistics	Research Laboratory.

       BUGS    
    

 Many Hosts	and Gateways ignore the	IPv4 RECORD_ROUTE option.

 The maximum IP header length is too small for options like	RECORD_ROUTE
 to	be completely useful.    There's not much	that can be done about this,
 however.

 Flood pinging is not recommended in general, and flood pinging the	broad-
 cast address should only be done under very controlled conditions.

 The    -v    
 option is not worth	much on	busy hosts.

FreeBSD	13.0		 November	20, 2022		 FreeBSD 13.0
  


Want to link to this manual page? Use this URL:

< https://man.freebsd.org/cgi/man.cgi?query=ping&manpath=FreeBSD+13.2-RELEASE+and+Ports
>


Inside a batch file on Windows, I use 7-zip
like this:

   ...\right_path\7z a output_file_name.zip file_to_be_compressed
  
  

How could I check the exit code of 7z
and take the appropriate action ?

asked Oct 1, 2010 at 4:47

Misha Moroshko's user avatar

Misha Moroshko

9 gold badges
26 silver badges
31 bronze badges

Test for a return code greater than or equal to 1:

   if ERRORLEVEL 1 echo Error
  
  
   if %ERRORLEVEL% NEQ 0 echo Error
  
  

or test for a return code equal to 0:

   if %ERRORLEVEL% EQU 0 echo OK
  
  

answered Oct 1, 2010 at 4:58

Dennis Williamson's user avatar

Dennis Williamson

19 gold badges
167 silver badges
187 bronze badges

This really works when you have: App1.exe calls -> .bat which runs –> app2.exe

   app2.exe
if %ERRORLEVEL% GEQ 1 EXIT /B 1
  
  

This is a check after app2 for errorlevel. If > 0, then the .bat exits and sets errorlevel to 1 for the calling app1.

answered Apr 19, 2013 at 5:07

Jonesome Reinstate Monica's user avatar

I had a batch script in Teamcity pipeline and it did not exit after it’s child script did exit with code 1.

To fix the problem I added this string IF %ERRORLEVEL% NEQ 0 EXIT 1
after the child script call.

   ...some code
call child-script.bat
IF %ERRORLEVEL% NEQ 0 EXIT 1
...some code
  
  

After the child script call exit result is saved to %ERRORLEVEL%
. If it did exit with an error %ERRORLEVEL%
would not be equal to 0 and in this case we exit with code 1 (error).

answered Apr 17, 2020 at 20:54

Michael Klishevich's user avatar

   cd.>nul | call Your_7z_File.Bat && Goto :Next || Goto :Error

:: Or...

cd.>nul | ...\right_path\7z.exe a output_file_name.zip file_to_be_compressed && Goto :Next || Goto :Error

  
  

1) Set errorlevel == 0

   cd.>nul  
  
   cd.>nul | call Your_7z_File.Bat  
  
   cd.>nul | call Your_7z_File.Bat && Goto :Next || Goto :Error  
  
   cd.>nul | call Your_7z_File.Bat && echo\Goto :Next || echo\Goto :Error  
  

answered Apr 18, 2020 at 17:35

Io-oI's user avatar

3 gold badges
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The test may also return an exit code. A program’s or utility’s exit code usually appears when it finishes or terminates.

The list below includes some of the non-zero exit codes (with their respective errors) that programs may return

Batch file error level

  IF %ERRORLEVEL% NEQ 0 (
 DO_Something
)  

A common method of returning error codes from batch files is to use the command EXIT /B %ERRORLEVEL%.

For custom return codes, use the EXIT /B <exitcodes>
command.

Example:

 In the below example, if the condition is met, the script will terminate with the exit code 0. If the condition isn’t met, then the exit code will be 1.

  if [[ "$(whoami)" != root ]]; then
 echo "Not root user."
 exit 1
fi
echo "root user"
exit 0  

FreeBSD Manual Pages

Loops

There have been statements enacted sequentially in the decision-making chapter. Alternatively, Batch Script can also be used to alter the flow of control in a program’s logic. These statements are then organized into flow control statements.

Looping through Command Line Arguments

For checking command-line arguments, you can use the for statement. Here is an example of how to loop through the arguments of a command line using the ‘for’ statement.

  for ((c=1; c<=7; c++))
do 
 echo "Welcome $c times"
done  

FreeBSD Manual Pages

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