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qsubst(1) [netbsd man page]

QSUBST(1)						    BSD General Commands Manual 						 QSUBST(1)

qsubst -- query-replace strings in files SYNOPSIS
qsubst str1 str2 [flags] file [file [...]] DESCRIPTION
qsubst reads its options (see below) to get a list of files. For each file on this list, it then replaces str1 with str2 wherever possible in that file, depending on user input (see below). The result is written back onto the original file. For each potential substitution found, the user is prompted with a few lines before and after the line containing the string to be substi- tuted. The string itself is displayed using the terminal's standout mode, if any. Then one character is read from the terminal. This is then interpreted as follows (this is designed to be like Emacs' query-replace-string): space Replace this occurrence and go on to the next one. . Replace this occurrence and don't change any more in this file (i.e., go on to the next file). , Tentatively replace this occurrence. The lines as they would look if the substitution were made are printed out. Then another character is read and it is used to decide the result as if the tentative replacement had not happened. n Don't change this one; just go on to the next one. ^G Don't change this one or any others in this file, but instead simply go on to the next file. ! Change the rest in this file without asking, then go on to the next file (at which point qsubst will start asking again). ? Print out the current filename and ask again. The first two arguments to qsubst are always the string to replace and the string to replace it with. The options are as follows: -w The search string is considered as a C symbol; it must be bounded by non-symbol characters. This option toggles. ('w' for 'word'.) -! -go -noask Enter ! mode automatically at the beginning of each file. -nogo -ask Negate -go, that is, ask as usual. -cN (Where N is a number.) Give N lines of context above and below the line with the match when prompting the user. -CAN (Where N is a number.) Give N lines of context above the line with the match when prompting the user. -CBN (Where N is a number.) Give N lines of context below the line with the match when prompting the user. -f filename The filename argument is one of the files qsubst should perform substitutions in. -F filename qsubst reads filename to get the names of files to perform substitutions in. The names should appear one to a line. The default amount of context is -c2, that is, two lines above and two lines below the line with the match. Arguments not beginning with a - sign in the options field are implicitly preceded by -f. Thus, -f is really needed only when the file name begins with a - sign. qsubst reads its options in order and processes files as it gets them. This means, for example, that a -go will affect only files named after the -go. The most context you can get is ten lines each, above and below. str1 is limited to 512 characters; there is no limit on the size of str2. Neither one may contain a NUL. NULs in the file may cause qsubst to make various mistakes. If any other program modifies the file while qsubst is running, all bets are off. AUTHORS
der Mouse <> BSD
September 4, 1999 BSD

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LEVENSHTEIN(3)								 1							    LEVENSHTEIN(3)

levenshtein - Calculate Levenshtein distance between two strings

int levenshtein (string $str1, string $str2) DESCRIPTION
int levenshtein (string $str1, string $str2, int $cost_ins, int $cost_rep, int $cost_del) The Levenshtein distance is defined as the minimal number of characters you have to replace, insert or delete to transform $str1 into $str2. The complexity of the algorithm is O(m*n), where n and m are the length of $str1 and $str2 (rather good when compared to simi- lar_text(3), which is O(max(n,m)**3), but still expensive). In its simplest form the function will take only the two strings as parameter and will calculate just the number of insert, replace and delete operations needed to transform $str1 into $str2. A second variant will take three additional parameters that define the cost of insert, replace and delete operations. This is more general and adaptive than variant one, but not as efficient. PARAMETERS
o $str1 - One of the strings being evaluated for Levenshtein distance. o $str2 - One of the strings being evaluated for Levenshtein distance. o $cost_ins - Defines the cost of insertion. o $cost_rep - Defines the cost of replacement. o $cost_del - Defines the cost of deletion. RETURN VALUES
This function returns the Levenshtein-Distance between the two argument strings or -1, if one of the argument strings is longer than the limit of 255 characters. EXAMPLES
Example #1 levenshtein(3) example <?php // input misspelled word $input = 'carrrot'; // array of words to check against $words = array('apple','pineapple','banana','orange', 'radish','carrot','pea','bean','potato'); // no shortest distance found, yet $shortest = -1; // loop through words to find the closest foreach ($words as $word) { // calculate the distance between the input word, // and the current word $lev = levenshtein($input, $word); // check for an exact match if ($lev == 0) { // closest word is this one (exact match) $closest = $word; $shortest = 0; // break out of the loop; we've found an exact match break; } // if this distance is less than the next found shortest // distance, OR if a next shortest word has not yet been found if ($lev <= $shortest || $shortest < 0) { // set the closest match, and shortest distance $closest = $word; $shortest = $lev; } } echo "Input word: $input "; if ($shortest == 0) { echo "Exact match found: $closest "; } else { echo "Did you mean: $closest? "; } ?> The above example will output: Input word: carrrot Did you mean: carrot? SEE ALSO
soundex(3), similar_text(3), metaphone(3). PHP Documentation Group LEVENSHTEIN(3)
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