grep : escape "*"

Dear R useRs,

Sorry for this foolish question, but I can't find how to escape the *
character when using grep :

grep("-", c("/3", "2*3", "4-4"))

[1] 3

grep("/", c("/3", "2*3", "4-4"))

[1] 1

grep("*", c("/3", "2*3", "4-4"))

Erreur dans grep("*", c("/3", "2*3", "4-4")) :
 expression r?guli?re incorrecte '*'
De plus : Warning message:
In grep("*", c("/3", "2*3", "4-4")) :
 erreur rgcomp : 'Expression r?guli?re pr?c?dente incorrecte'

grep("\*", c("/3", "2*3", "4-4"))

Erreur dans grep("*", c("/3", "2*3", "4-4")) :
 expression r?guli?re incorrecte '*'
De plus : Warning messages:
1: '\*' est un code escape non reconnu dans une cha?ne de caract?res
2: code escape non reconnu ?limin? de "\*"
3: In grep("*", c("/3", "2*3", "4-4")) :
 erreur rgcomp : 'Expression r?guli?re pr?c?dente incorrecte'

Best regards,

david

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