security - Is it Safe editing the CronTab with PHP? -

i'm building script this tuts append , remove cronjob admin part of website made php.

is safe implement on server ? issues ?

thanks

maybe that:

list of script in crontab (f.e.):

#script1 #script2 #script3 

i'm removing script crontab:

crontab -l | grep -v "#script1" > crontab.txt && crontab crontab.txt 

list of script in crontab after edit:

#script2 #script3 

command crontab -l | grep -v "#script1" > crontab.txt && crontab crontab.txt can run exec() function.

i hope helped.