Re: [NTG-pdftex] a wrapper for using pdftex as a library call

31 Jan 2007


      On 1/31/07, Thanh Han The  wrote:
...
Hi,
I am working on a wrapper in C so that application can call pdftex
via a library call. Can you please have a look at the proposed API
and comment on it if you find a potential problem? I attached two files:
test0.c: a minimal test file
test1.c: the same file with comments
Thanks,
Thanh
the attachments seem to be discarded by the listserv, so I resend the
files as inline text:

test0.c:
==========================
#include "runptex.h"

int main()
{
    pdftex_data_struct tmp;

    if (init_pdftex_data(&tmp,
                         "/home/thanh/runptex/good-file.tex",
                         "/home/thanh/tmp/runptex",
                         "-fmt=pdflatex"
                        ) != 0)
        pds_print_error_and_exit(&tmp);

    if (run_pdftex(&tmp) != 0)
        pds_print_error_and_exit(&tmp);

    printf("running pdftex succeeded, the output is %s in directory %s\n",
            tmp.pdf_file, tmp.working_dir);

    destroy_pdftex_data(&tmp);
    return 0;
}
==========================

test1.c:
==========================
#include "runptex.h"

int main()
{
    pdftex_data_struct tmp;
    /* pdftex_data_struct is defined in runptex.h as follows:
    typedef struct {
        char *tex_file;
        char *pdf_file;
        char *log_file;
        char *working_dir;
        char *pdftex_opts;
        int return_code;
        char *return_msg;
    } pdftex_data_struct;
    */

    if (init_pdftex_data(&tmp,
                         "/home/thanh/runptex/good-file.tex",
                         "/home/thanh/tmp/runptex",
                         "-fmt=pdflatex") != 0)
    /*
    Prototype:
    int init_pdftex_data(pdftex_data_struct *pds, const char *tex_file,
                         const char *working_dir, const char *pdftex_opts);
    Description:
    initialize pds as follows:
    - sets all fields of pds to NULL/0
    - checks that tex_file and working_dir are:
        - not null
        - not too long (< MAX_FILENAME_LENGTH)
        - contains only allowed characters (defined by is_path_char())
        - absolute (full) path
    - checks that tex filename (the last component of tex_file):
        - contains only allowed characters (defined by is_filename_char())
        - has extension '.tex'
    - checks that pdftex_opts contains only allowed characters
(defined by is_option_char())
    - checks that tex_file can be read
    - checks that working_dir is a directory
    - store relevant strings (paths, pdf/log filenames, etc.) in pds

    Return: 0 if ok, otherwise pds->return_code (>0 in case of error)
    */
        pds_print_error_and_exit(&tmp);
    /*
    Prototype:
    void pds_print_error_and_exit(pdftex_data_struct *pds);

    Description:
    a helper function for testing purpose; just print the error
message stored in pds
    and exit the program
    */

    if (run_pdftex(&tmp) != 0)
    /*
    prototype:
    int run_pdftex(pdftex_data_struct *pds);

    description:
    execute pdftex as follows:
    - construct the argument to call pdftex from pds->tex_file and
pds->pdftex_opts
    - change working dir to pds->working_dir
    - try to create an empty pdf file and an empty log file to verify
file permissions
    - copy pds->tex_file to the working directory
    - run system() to excecute the pdftex command constructed above
    - checks whether the log file has been created
    - checks whether the log file contains any error, ie line(s)
beginning with '!'
    - checks whether the pdf file has been created
    - check for the pdf header mark and eof mark
    */
        pds_print_error_and_exit(&tmp);

    printf("running pdftex succeeded, the output is %s in directory %s\n",
            tmp.pdf_file, tmp.working_dir);

    destroy_pdftex_data(&tmp);
    /*
    Prototype:
    void destroy_pdftex_data(pdftex_data_struct *pds);

    Description:
    free the strings stored in pds
    */

    return 0;
}
==========================