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120 lines
4.8 KiB
Plaintext
120 lines
4.8 KiB
Plaintext
Common String Handling 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, and any character
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array with length[128] will not overflow.
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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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For functions that operate on two string, one of the strings is specified
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using the setdst() function from module stddef. Unless otherwise noted,
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none of the functions change dstptr.
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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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n = strlen(s); Returns length of string.
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Note: Sets srcptr to &s.
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n = 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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Note: Sets srcptr to &s.
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n = strrch(c, s); Returns position of last occurance of character
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in string, or 255 if character was not found.
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Note: Sets srcptr to &s.
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n = strcat(s); Concatenates source string s onto the end of
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destination string set by prior setdst() call.
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Returns total length of concatenated string.
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Note: Sets srcptr to &s.
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c = strcmp(s); Compares source string s against destination
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string set by prior setdst() 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: Sets srcptr to &s.
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n = strcpy(s); Copies wource string s into destination string set
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by prior setdst() call, replacing previous contents.
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Returns number of characters copied.
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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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setdst(&d); strcpy(s); s[n]=0;
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Note: Sets srcptr to &s.
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n = strstr(s); Searches for string s in destination string set.
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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 strcmp(), leaving srcptr pointing to
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the matched string in the destination string
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(or the end if not found).
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These functions are not part of the standard C and C++ string libraries.
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They are included because they are more efficient than equivalent C02 code.
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strcpb(s) Copies string s to the system buffer (sysbfr).
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Note: sets srcptr to &s and dstptr to &sysbfr,
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then calls strcpy().
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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 setdst() call,
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replacing previous contents.
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Returns number of characters copied.
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To copy a substring starting at position n with
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length i from string s to string d, the following
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code can be used:
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setdst(&d); strcut(s, n); s[i] = 0;
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Note: Sets srcptr to the address of position n
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in s and calls strcpy().
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Note: This library expects the following functions to be defined
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setdst(s); Set destination pointer
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setsrc(s); Set source pointer and initialize index
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along with the zero page variable pairs
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srcptr Source String Pointer
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dstptr 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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