replace words in a file
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The task is to replace - looks for all occurrences of string from and replaces it with string to. It is possible to specify one or more files on which to perform the replace operation(s) in a single replace command. and this is my code: void replace(char* OldWord, char* NewWord) { char *result = NULL; char buff[1000]; char c; char line[1000]; FILE * f = fopen ("file1.txt", "r+"); int count=0; while (fgets(buff, sizeof(buff), f)) { result = replaceWord(buff, OldWord, NewWord); // } // //free(result); } char *replaceWord(const char *s, const char *oldW,const char *newW) { char *result; int i, cnt = 0; int newWlen = strlen(newW); int oldWlen = strlen(oldW); static int k=0; k++; char newline[1000]; FILE * fp; // printf("%s\n",oldW); //printf("%s\n",newW); // Counting the number of times old word // occur in the string for (i = 0; s[i] != '\0'; i++) { if (strstr(&s[i], oldW) == &s[i]) { cnt++; // Jumping to index after the old word. i += oldWlen - 1; } } // Making new string of enough length result = (char *)malloc(i + cnt * (newWlen - oldWlen) + 1); i = 0; while (*s) { // compare the substring with the result if (strstr(s, oldW) == s) { strcpy(&result[i], newW); i += newWlen; s += oldWlen; fp = fopen ("file1.txt", "w"); rewind(fp); fseek(fp,i-newWlen,SEEK_SET); fprintf(fp,"%s\n",result); } else { result[i++] = *s++; } } result[i] = '\0'; fp = fopen ("file1.txt", "w"); fprintf(fp,"%s\n",result); // printf("%d\n",k); return result; } the replace function does not give the desired output The command line looks like: ./a.out replace old_word new_word files.txt must replace old_word with the new_word in all files.
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The task is to replace - looks for all occurrences of string from and replaces it with string to. It is possible to specify one or more files on which to perform the replace operation(s) in a single replace command. and this is my code: void replace(char* OldWord, char* NewWord) { char *result = NULL; char buff[1000]; char c; char line[1000]; FILE * f = fopen ("file1.txt", "r+"); int count=0; while (fgets(buff, sizeof(buff), f)) { result = replaceWord(buff, OldWord, NewWord); // } // //free(result); } char *replaceWord(const char *s, const char *oldW,const char *newW) { char *result; int i, cnt = 0; int newWlen = strlen(newW); int oldWlen = strlen(oldW); static int k=0; k++; char newline[1000]; FILE * fp; // printf("%s\n",oldW); //printf("%s\n",newW); // Counting the number of times old word // occur in the string for (i = 0; s[i] != '\0'; i++) { if (strstr(&s[i], oldW) == &s[i]) { cnt++; // Jumping to index after the old word. i += oldWlen - 1; } } // Making new string of enough length result = (char *)malloc(i + cnt * (newWlen - oldWlen) + 1); i = 0; while (*s) { // compare the substring with the result if (strstr(s, oldW) == s) { strcpy(&result[i], newW); i += newWlen; s += oldWlen; fp = fopen ("file1.txt", "w"); rewind(fp); fseek(fp,i-newWlen,SEEK_SET); fprintf(fp,"%s\n",result); } else { result[i++] = *s++; } } result[i] = '\0'; fp = fopen ("file1.txt", "w"); fprintf(fp,"%s\n",result); // printf("%d\n",k); return result; } the replace function does not give the desired output The command line looks like: ./a.out replace old_word new_word files.txt must replace old_word with the new_word in all files.
Member 12957547 wrote:
It is possible to specify one or more files on which to perform the replace operation(s) in a single replace command.
Why "in a single replace command"? Why not just open your files in the loop and perform the replacement in each file? :confused:
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Member 12957547 wrote:
It is possible to specify one or more files on which to perform the replace operation(s) in a single replace command.
Why "in a single replace command"? Why not just open your files in the loop and perform the replacement in each file? :confused:
because I do not know how many items get from the CLI
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The task is to replace - looks for all occurrences of string from and replaces it with string to. It is possible to specify one or more files on which to perform the replace operation(s) in a single replace command. and this is my code: void replace(char* OldWord, char* NewWord) { char *result = NULL; char buff[1000]; char c; char line[1000]; FILE * f = fopen ("file1.txt", "r+"); int count=0; while (fgets(buff, sizeof(buff), f)) { result = replaceWord(buff, OldWord, NewWord); // } // //free(result); } char *replaceWord(const char *s, const char *oldW,const char *newW) { char *result; int i, cnt = 0; int newWlen = strlen(newW); int oldWlen = strlen(oldW); static int k=0; k++; char newline[1000]; FILE * fp; // printf("%s\n",oldW); //printf("%s\n",newW); // Counting the number of times old word // occur in the string for (i = 0; s[i] != '\0'; i++) { if (strstr(&s[i], oldW) == &s[i]) { cnt++; // Jumping to index after the old word. i += oldWlen - 1; } } // Making new string of enough length result = (char *)malloc(i + cnt * (newWlen - oldWlen) + 1); i = 0; while (*s) { // compare the substring with the result if (strstr(s, oldW) == s) { strcpy(&result[i], newW); i += newWlen; s += oldWlen; fp = fopen ("file1.txt", "w"); rewind(fp); fseek(fp,i-newWlen,SEEK_SET); fprintf(fp,"%s\n",result); } else { result[i++] = *s++; } } result[i] = '\0'; fp = fopen ("file1.txt", "w"); fprintf(fp,"%s\n",result); // printf("%d\n",k); return result; } the replace function does not give the desired output The command line looks like: ./a.out replace old_word new_word files.txt must replace old_word with the new_word in all files.
Haven't tried to run your code, but I do notice a couple things: 1: you call
fopen()several times, but there's no correspondingfclose(). If you had a large file (say the text of the bible), and wanted to replace, "god" with "jimmy", you would probably run out of file handles before completing the task. 2: you continually callfopenon the same file.fopen("file1.txt", "w")truncates the file, so some future read may return EOF unexpectedly. [NB not necessarily the next read, as the call tofgetsmight fill an input buffer, which following calls use, rather than continually reading from the file] My suggestion would be to open a temporary file and write your output there, then copy or replace the input file with the temp file.tmpfile()might be useful, here. 3:fgets()reads up to size-1 bytes from the input stream. What happens if you have very long lines (over 999 chars, in your case), and the word you want occupies chars 996-1003? You'll get the first 3 chars in one read and the remaining 4 in the next, missing an occurrence. Might I suggest you look atgetline(). 4: do you need to concern yourself with word case? Do you need to replace "babble" with "brook", "Babble" with "Brook" and "BABBLE" with "BROOK"? -
because I do not know how many items get from the CLI
Member 12957547 wrote:
because I do not know how many items get from the CLI
Yes, you do, or at least
main()does.int main(int argc, char **argv)
argcis the number of arguments passed to main, andargvis an array of strings containing the command line arguments. Remeber thatargv[0]is the program name, so argc is always > 0. The following will print all the command line arguments#include
int main(int argc, char **argv)
{
for(int i = 0; i < argc; ++i)
printf("argv[%d] = \"%s\"\n", i, argv[i];
return0;
} -
The task is to replace - looks for all occurrences of string from and replaces it with string to. It is possible to specify one or more files on which to perform the replace operation(s) in a single replace command. and this is my code: void replace(char* OldWord, char* NewWord) { char *result = NULL; char buff[1000]; char c; char line[1000]; FILE * f = fopen ("file1.txt", "r+"); int count=0; while (fgets(buff, sizeof(buff), f)) { result = replaceWord(buff, OldWord, NewWord); // } // //free(result); } char *replaceWord(const char *s, const char *oldW,const char *newW) { char *result; int i, cnt = 0; int newWlen = strlen(newW); int oldWlen = strlen(oldW); static int k=0; k++; char newline[1000]; FILE * fp; // printf("%s\n",oldW); //printf("%s\n",newW); // Counting the number of times old word // occur in the string for (i = 0; s[i] != '\0'; i++) { if (strstr(&s[i], oldW) == &s[i]) { cnt++; // Jumping to index after the old word. i += oldWlen - 1; } } // Making new string of enough length result = (char *)malloc(i + cnt * (newWlen - oldWlen) + 1); i = 0; while (*s) { // compare the substring with the result if (strstr(s, oldW) == s) { strcpy(&result[i], newW); i += newWlen; s += oldWlen; fp = fopen ("file1.txt", "w"); rewind(fp); fseek(fp,i-newWlen,SEEK_SET); fprintf(fp,"%s\n",result); } else { result[i++] = *s++; } } result[i] = '\0'; fp = fopen ("file1.txt", "w"); fprintf(fp,"%s\n",result); // printf("%d\n",k); return result; } the replace function does not give the desired output The command line looks like: ./a.out replace old_word new_word files.txt must replace old_word with the new_word in all files.
Member 12957547 wrote:
the replace function does not give the desired output
If that is the case, I'd take a step back and get it working before worrying about files. Just send the function a string of characters, and the find/replace terms. After that, then rope the file contents back in.
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The task is to replace - looks for all occurrences of string from and replaces it with string to. It is possible to specify one or more files on which to perform the replace operation(s) in a single replace command. and this is my code: void replace(char* OldWord, char* NewWord) { char *result = NULL; char buff[1000]; char c; char line[1000]; FILE * f = fopen ("file1.txt", "r+"); int count=0; while (fgets(buff, sizeof(buff), f)) { result = replaceWord(buff, OldWord, NewWord); // } // //free(result); } char *replaceWord(const char *s, const char *oldW,const char *newW) { char *result; int i, cnt = 0; int newWlen = strlen(newW); int oldWlen = strlen(oldW); static int k=0; k++; char newline[1000]; FILE * fp; // printf("%s\n",oldW); //printf("%s\n",newW); // Counting the number of times old word // occur in the string for (i = 0; s[i] != '\0'; i++) { if (strstr(&s[i], oldW) == &s[i]) { cnt++; // Jumping to index after the old word. i += oldWlen - 1; } } // Making new string of enough length result = (char *)malloc(i + cnt * (newWlen - oldWlen) + 1); i = 0; while (*s) { // compare the substring with the result if (strstr(s, oldW) == s) { strcpy(&result[i], newW); i += newWlen; s += oldWlen; fp = fopen ("file1.txt", "w"); rewind(fp); fseek(fp,i-newWlen,SEEK_SET); fprintf(fp,"%s\n",result); } else { result[i++] = *s++; } } result[i] = '\0'; fp = fopen ("file1.txt", "w"); fprintf(fp,"%s\n",result); // printf("%d\n",k); return result; } the replace function does not give the desired output The command line looks like: ./a.out replace old_word new_word files.txt must replace old_word with the new_word in all files.
A couple of things I've noticed: 1. You are always using 'file1.txt' in your code, not the filename(s) passed as argument 2. As has been pointed out, lines can be longer than 1000 chars. 3. You never close the file you've opened. That will cause changes in one file buffer to overwrite previous changes once the files are closed (or at the end of the program). 4. You only check for one occurence of a word per line. What if there are multiple occurrences? Suggestions: - As already pointed out, start with your replace functions and make sure they work as intended, before dealing with files! - Make sure you always close the files you've opened - Write the modified text into another, temporary file. Later erase the original file, and rename the temporary one. That way you can just keep on reading/writing without needing to close/open the file over and over again.
GOTOs are a bit like wire coat hangers: they tend to breed in the darkness, such that where there once were few, eventually there are many, and the program's architecture collapses beneath them. (Fran Poretto)