strcspn : count chars not in string

Synopsis

size_t strcspn(const char *s1, const char *s2);
```### Description

This function computes the length of the initial part of the string pointed to by s1 which consists entirely of characters NOT from the string pointed to by s2 (excluding the terminating null character).### Returns

strcspn returns the length of the substring found.

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**Authoritative source**: BUSMASTER DITA help source `strcspn.dita`, compiled into `BUSMASTER.CHM` with the application.