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NSPR Reference
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Chapter 16   String Operations

This chapter describes some of the key NSPR functions for manipulating strings. Libraries built on top of NSPR, such as the Netscape security libraries, use these functions to manipulate strings. If you are copying or examining strings for use by such libraries or freeing strings that were allocated by such libraries, you must use these NSPR functions rather than the libc equivalents.

PL_strlen
PL_strcpy
PL_strdup
PL_strfree

PL_strlen

Returns the length of a specified string (not including the trailing '\0')


Syntax 
PRUint32 PL_strlen(const char *str);


Parameter
This function has the following parameter: 

str

Size in bytes of item to be allocated.


Returns
If successful, the function returns length of the specified string.

PL_strcpy

Copies a string, up to and including the trailing '\0', into a destination buffer.


Syntax
char * PL_strcpy(char *dest, const char *src);


Parameters
This function has the following parameters: 

dest

Pointer to a buffer. On output, the buffer contains a copy of the string passed in src. 

src

Pointer to the string to be copied.


Returns
The function returns a pointer to the buffer specified by the dest parameter.


Description
If the string specified by src is longer than the buffer specified by dest, the buffer will not be null-terminated.

PL_strdup

Returns a pointer to a new memory node in the NSPR heap containing a copy of a specified string.


Syntax 
char *PL_strdup(const char *s);


Parameter
This function has the following parameter: 

s

Size in bytes of item to be allocated.


Returns
The function returns one of these values:

  • If successful, a pointer to a copy of the specified string.

  • If the memory allocation fails, NULL.


Description
To accommodate the terminator, the size of the allocated memory is one greater than the length of the string being copied. A NULL argument, like a zero-length argument, results in a pointer to a one-byte block of memory containing the null value.

PL_strfree

Frees memory allocated by PL_strdup.


Syntax 
void PL_strfree(char *s);


Parameter
This function has the following parameter: 

s

Pointer to the string to be freed.

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Last Updated May 18, 2001