diff options
| -rw-r--r-- | main.c | 4 | ||||
| -rw-r--r-- | replace.c | 46 |
2 files changed, 50 insertions, 0 deletions
@@ -1,4 +1,5 @@ #include <stdio.h> +#include <stdlib.h> #include "replace.h" int @@ -8,5 +9,8 @@ main(void) ret = replaceinfile("input.txt", "output.txt", "%PLACEHOLDER%", "replacement string"); if (ret == 0) puts("failed"); + char *rep = replaceinmemory("this string this string is a test string", "string", "word"); + printf("%s\n", rep); + free(rep); return 0; } @@ -37,6 +37,14 @@ getfilelength(FILE *fp) return retval; } +void +replaceappendchar(char *dest, char ch) +{ + int len = strlen(dest); + dest[len] = ch; + dest[len+1] = '\0'; +} + int replaceinfile(char *originalfile, char *destinationfile, char *placeholder, char *replacement) { @@ -78,3 +86,41 @@ replaceinfile(char *originalfile, char *destinationfile, char *placeholder, char free(filebuffer); return 1; } + +char * +replaceinmemory(char *src, char *placeholder, char *replacement) +{ + /* + * replace every placeholder with replacement in source src + * return pointer to string, NULL if no placement found + * user must free the returned memory + */ + char *dest = NULL; + size_t destsize; + char *substr = strstr(src, placeholder); + if (!substr) + return NULL; + /* initial dest size if only one placeholder exists */ + destsize = (strlen(src)-strlen(placeholder))+strlen(replacement+1); + dest = malloc(destsize); + if (!dest) + return NULL; + dest[0] = '\0'; /* junk in memory, we need [0] to be null for strlen() later */ + for (size_t i = 0; i < strlen(src); i++) + { + if (i == (substr-src)) + { + i += strlen(placeholder); + substr++; + substr = strstr(substr, placeholder); + if (substr) + { + destsize = (destsize-strlen(placeholder))+strlen(replacement)+1; + dest = realloc(dest, destsize); + } + strcat(dest, replacement); + } + replaceappendchar(dest, src[i]); + } + return dest; +} |