The Atari Compendium/The Atari Compendium (Toad Computers) (1994).iso/files/prgtools/programm.ing/dlibs12.arc/GIFTS.ARC/SSED.C

C/C++ Source or Header | 1988-10-19 | 4.0 KB | 207 lines

/*
 * SSED        substitution stream editor (a very small subset of SED)
 */

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

char        lnbuf[512];        /* line buffer */
char        **old = NULL;        /* old string list (search for) */
char        **new = NULL;        /* new string list (replace with) */
int        s_flag = FALSE;        /* modify files "in place" */

typedef    char    **LIST;

int lstlen(list)
    register LIST list;
    {
    register int len = 0;

    if(list == NULL)
        return(0);
    while(*list++)
        ++len;
    return(len);
    }

LIST lstcat(list, item)
    register LIST list;
    register char *item;
    {
    register int len;

    len = lstlen(list);
    list = (LIST) realloc(list, (len + 2) * sizeof(char *));
    if(list == NULL)
        return(NULL);
    list[len] = item;
    list[len+1] = NULL;
    return(list);
    }

version()
    {
    printf("ssed v1.2 -- 10/19/88 by Dale Schumacher\n");
    exit(1);
    }

usage()
    {
    fprintf(stderr,
"usage: ssed [-s] [-e command] [-f commandfile] [infile...] >outfile\n");
    fprintf(stderr,
"    -s    files are modified in place (standalone).\n");
    fprintf(stderr,
"    -e    s/oldtext/newtext/ command on the command line.\n");
    fprintf(stderr,
"    -f    s/oldtext/newtext/ commands read from a file.\n");
    exit(EXIT_FAILURE);
    }

main(argc, argv)
    int argc;
    char *argv[];
    {
    FILE *fp, *ftmp;        /* working and temporary files */
    char *fname;            /* working file name */
    char tname[128];        /* temporary file name */
    int c;
    extern int optind;
    extern char *optarg;

    while((c = getopt(argc, argv, "se:f:V")) != EOF)
        {
        switch(c)
            {
            case 's':
                s_flag = TRUE;
                break;
            case 'e':
                parse(optarg);
                break;
            case 'f':
                if((fp = fopen(optarg, "r")) == NULL)
                    {
                    perrorf("can't open command file '%s'",
                        optarg);
                    exit(EXIT_FAILURE);
                    }
                errno = 0;
                while(fgets(lnbuf, sizeof(lnbuf), fp))
                    parse(lnbuf);
                fclose(fp);
                if(errno)
                    perror(optarg);
                break;
            case 'V':
                version();
            case '?':
                usage();
            }
        }
    if(old == NULL)            /* no commands specified */
        usage;
    if(optind >= argc)        /* no files specified */
        {
        if(isatty(stdin) || s_flag)
            usage();
        else
            ssed(stdin, stdout);
        }
    else
        {
        for(; optind < argc; ++optind)
            {
            fname = argv[optind];
            if(!strcmp(fname, "-"))
                fp = stdin;
            else if((fp = fopen(fname, "r")) == NULL)
                {
                perrorf("can't open file '%s'", fname);
                exit(EXIT_FAILURE);
                }
            if(s_flag)
                {
                tmpnam(tname);
                if((ftmp = fopen(tname, "w")) == NULL)
                    {
                    perrorf("can't open temp file '%s'",
                        tname);
                    exit(EXIT_FAILURE);
                    }
                }
            else
                ftmp = stdout;
            errno = 0;
            ssed(fp, ftmp);
            fclose(fp);
            if(s_flag)
                {
                fclose(ftmp);
                unlink(fname);
                if(rename(tname, fname) != 0)
                    {
                    perrorf("can't rename '%s' to '%s'.\n",
                        tname, fname);
                    exit(EXIT_FAILURE);
                    }
                }
            if(errno)
                perror(NULL);
            }
        }
    exit(EXIT_SUCCESS);
    }

parse(cmd)
    register char *cmd;
    {
    register char *p, *q;
    register char delim;
    char buf[512];

    if(!(cmd && *cmd))
        return;
    cmd = strcpy(buf, cmd);
    if(tolower(*cmd) != 's')
        {
        fprintf(stderr,
        "ssed: only 's/oldtext/newtext/' commands are implemented.\n");
        exit(EXIT_FAILURE);
        }
    if(((delim = cmd[1]) == '\0')
    || ((q = strchr((cmd + 2), delim)) == NULL)
    || ((p = strchr((q + 1), delim)) == NULL))
        {
        fprintf(stderr, "ssed: bad command syntax '%s'\n", cmd);
        exit(EXIT_FAILURE);
        }
    *p = '\0';
    *q++ = '\0';
    p = cmd + 2;
    if(((old = lstcat(old, strdup(p))) == NULL)
    || ((new = lstcat(new, strdup(q))) == NULL))
        {
        fprintf(stderr, "ssed: out of memory.\n");
        exit(EXIT_FAILURE);
        }
    }

ssed(fin, fout)
    FILE *fin, *fout;
    {
    register char **pp, **qq;

    while(fgets(lnbuf, sizeof(lnbuf), fin))
        {
        for(pp = old, qq = new; *pp && *qq; ++pp, ++qq)
            {
            strrpl(lnbuf, *pp, *qq, -1);
            }
        fputs(lnbuf, fout);
        }
    }