/*
program to allow for wild card renaming of files
*/

#include <stdio.h>
#include <errno.h>
#include <string.h>

static char obuf[50], nbuf[50], cmd[110];

main(argc,argv)
int argc; char *argv[];
{
	int i, ip, ier, mode;
	char *pt;

	if(argc < 4)
	{
		fprintf(stderr,"rename files, changing oldstring to newstring within the names.\n");
		fprintf(stderr,"syntax: renamer oldstr newstr file[s]\n");
		fprintf(stderr,"        oldstr -> old substring within filenames\n");
		fprintf(stderr,"        newstr -> new substring within filenames\n");
		fprintf(stderr,"        files  -> files to be renamed, wildcards valid.\n");
		fprintf(stderr,"If oldstr = \\^  append newstr to beginning of filenames.\n");
		fprintf(stderr,"If oldstr = \\$  append newstr to end of filenames.\n");
		fprintf(stderr,"WARNING : existing files with same target name will be replaced.\n");
		fprintf(stderr,"Example : Given \"file1.dat file2.dat file3.dat\",\n");
        fprintf(stderr,"rename them all to \"file1.data file2.data file3.data\"\n");
        fprintf(stderr,"Type the following : \"renamer dat data file?.dat\"\n");
		fprintf(stderr,"tjmartin@anl.gov 10/15/97\n");
		exit(1);
	}
	mode = 0;		/* assume normal replace mode */
	if(argv[1][0]=='^') mode = 1;	/* use prepend mode */
	if(argv[1][0]=='$') mode = 2;	/* use append mode */
	for(i=3; i<argc; i++)
	{
		strcpy(obuf,argv[i]);	/* put next file name into obuf */
		ier=0;
		switch(mode)
		{
			case 0:
				pt = strstr(obuf,argv[1]);	/* find string to replace */
				ip = (int)(pt-obuf);
				if(pt)
				{
					strncpy(nbuf,obuf,ip);	/* copy leading chars to remain */
					nbuf[ip] = 0;				/* add a null */
					strcat(nbuf,argv[2]);		/* append newstr */
					strcat(nbuf,&obuf[ip+strlen(argv[1])]);	/* append trailer */
				}
				else
				{
					printf("renamer cannot find substring %s in filename %s\n",argv[1],argv[i]);
					ier=1;
				}
				break;
			case 1:
				strcpy(nbuf,argv[2]);	/* prepend newstr */
				strcat(nbuf,obuf);		/* to oldname */
				break;
			case 2:
				strcpy(nbuf,obuf);		/* get oldname */
				strcat(nbuf,argv[2]);	/* append newstr */
				break;
		}
		if(ier==0) sprintf(cmd,"mv %s %s",obuf,nbuf);
		printf("%s\n",cmd);
		ier = system(cmd);
		if(ier > 0) { perror("renamer error"); exit(errno); }
	}
	exit(0);
}