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140 lines
6.0 KiB
Plaintext
140 lines
6.0 KiB
Plaintext
Common String Manipulation Functions for C02
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Strings are zero-terminated arrays of type char with a maximum length
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of 128 characters.
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The first character in a string is at position 0, and the last character
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is at position length minus 1.
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Since all of the routines stop processing at the 128th character, a 128
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character string does not require a zero terminator.
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Due to the limitations of parameter passing in C02, the argument lists of
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most of these functions do not match those in standard C and C++.
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Usage: at the beginning of the program use the directives
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#include <stddef.h02>
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#include <string.h02>
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The following functions are defined:
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p = strapd(c, &s); Append character c to string s.
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Returns length of new string.
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If the string length exceeds 127 prior to the
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append, no action is taken and the existing
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length is returned.
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This function is not part of the standard C and
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C++ string libraries. It is included because it
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is more efficient than the equivalent C02 code.
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p = strchr(c, &s); Searches string s for character c.
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Returns position of first occurance of character
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in string, or 255 if character was not found.
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n = strlen(&s); Determines length of string s.
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Returns length of string.
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p = strrch(c, &s); Searches end of string s for character c.
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Returns position of last occurance of character
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in string, or 255 if character was not found.
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strdst(&d); Sets string d as the destination string for subsequent
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strcat(). strcmp(), strcpy(), and strstr() calls.
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This function is not part of the standard C and
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C++ string libraries. It is needed because of the
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parameter passing limitations of C02.
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Note: Aliased to the setdst() routine which sets
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variables dstlo and dsthi as a pointer to the string.
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n = strcat(&s); Concatenates source string s onto the end of
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destination string set by prior strdst() call.
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Returns total length of concatenated string.
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Note: dstlo and dsthi are left pointing to the
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destination string.
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c = strcmp(&s); Compares source string s against destination
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string set by prior strdst() call.
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Returns 255 if destination < source, 0 if
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destination = source, and 1 if destination > source.
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These results can be evaluated using the C02
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unary comparator ! or the test-operators :+ or :-.
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Note: dstlo and dsthi are left pointing to the
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destination string.
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n = strcpy(&s); Copies wource string s into destination string set
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by prior strdst() call, replacing previous contents.
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Returns number of characters copied.
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Note: dstlo and dsthi are left pointing to the
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destination string.
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To copy the first n characters from string s to
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string d, the following code can be used:
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strdst(&d); strcpy(&s); s[n]=0;
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n = strcut(n, &s); Copies from source string s, starting at position n,
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into destination string set by prior strdst() call,
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replacing previous contents.
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Returns number of characters copied.
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This function is not part of the standard C and
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C++ string libraries. It is included because
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it is faster and more compact tham the equivalent
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C02 code.
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To copy a substring starting at position n with
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length l from string s to string d, the following
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code can be used:
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strdst(&d); strcut(&s, n); s[l]=0;
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Note: calls routine strcat(). leaving dstlo and
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dsthi pointing to the destination string, along
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with strlo and strhi pointing to the address of
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position n in the source string.
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p = strstr(&s); Searches for destination string s in source string
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set by prior strdst() call.
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Returns position of source string in destination
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string, or 255 if character was not found.
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Note: calls routine strcmp(), leaving dstlo and
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dsthi pointing to the address of the position of
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the source string in the destination string (or
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the end of the destination string if the source
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string was not found).
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Note: This library expects the following functions to be defined
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setdst(&s); Set destination string pointer
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setsrc(&s); Set source string pointer and initialize index
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along with the zero page variable pairs
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strlo, strhi Source String Pointer
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dstlo, dsthi Destination String Pointer
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as well as the transient variables
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temp0 Temporary storage
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temp1
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