c - Working example of substitution using PCRS -

i need to substitution in string in c. recommended in 1 of answers here how regex string replacements in pure c? use pcrs library. downloaded pcrs here ftp://ftp.csx.cam.ac.uk/pub/software/programming/pcre/contrib/ i'm confused how use it. below code (taken se post)

            const char *error;             int   erroffset;             pcre *re;             int   rc;             int   i;             int   ovector[100];              char *regex = "from:([^@]+).*";             char str[]  = "from:regular.expressions@example.com\r\n";             char stringtobesubstituted[] = "gmail.com";              re = pcre_compile (regex,          /* pattern */                                pcre_multiline,                                &error,         /* error message */                                &erroffset,     /* error offset */                                0);             /* use default character tables */             if (!re)             {                 printf("pcre_compile failed (offset: %d), %s\n", erroffset, error);                 return -1;             }              unsigned int offset = 0;             unsigned int len = strlen(str);             while (offset < len && (rc = pcre_exec(re, 0, str, len, offset, 0, ovector, sizeof(ovector))) >= 0)             {                 for(int = 0; < rc; ++i)                 {                     printf("%2d: %.*s\n", i, ovector[2*i+1] - ovector[2*i], str + ovector[2*i]);                 }                 offset = ovector[1];             } 

as opposed 'pcre_compile' , 'pcre_exec' functions need use pcrs?

thanks.

simply follow instructions in install file:

to build pcrs, need pcre 3.0 or later , gcc.

installation easy: ./configure && make && make install debug mode can enabled --enable-debug.

there simple demo application (pcrsed) included.

pcrs provides following functions documented in man page pcrs.3:

• pcrs_compile
• pcrs_compile_command
• pcrs_execute
• pcrs_execute_list
• pcrs_free_job
• pcrs_free_joblist
• pcrs_strerror

here's online version of man page. use these functions, include header file pcrs.h , link program against pcrs library using linker flag -lpcrs.