Detailed explanation of how to enable GD library support in PHP_PHP Tutorial

Opening the GD library is an important parameter in PHP. It is often used to process images. Any processing of images requires the support of the GD library. Below I will introduce the methods and commands for opening the GD library in various systems. You can refer to it. .

Enable PHP GD library support under Windows

Find php.ini, open the content and find:

;extension=php_gd2.dll

Remove the semicolon ";" at the front and save it. If there is no semicolon in the first place, it means it is already enabled.

Enable PHP GD library support under Linux

#There are several ways to enable GD library support
## Check whether the GD library is installed or not using the command
php5 -m | grep -i gd
Or
php -i | grep -i --color gd
##If the GD library is not installed, install it on the server. The method is as follows
### If it is a source code installation, add the parameter
--with-gd
### If it is a Debian Linux system, use apt-get to install it, as follows
apt-get install php5-gd
### If it is a CentOS system, use yum to install it, as follows
yum install php-gd
### If it is a suse-based Linux system, use yast to install it, as follows
yast -i php5_gd
### If you think this world is not painful enough, you can add
when the original compiled PHP does not support GD. First download the zlib source code, libpng source code, and gd source code
After unzipping, go to the source code directory
zlib directory
./configure --prefix=/usr/local/zlib
make ; make install
make clean
libpng directory
cp scripts/makefile.linux ./makefile
./configure --prefix=/usr/local/libpng
make ; make install
make clean
gd directory
./configure --prefix=/usr/local/libgd --with-png=/usr/local/libpng
make ; make install
make clean
Finally, in php.ini, after searching for [gd], add a line below
extension=/usr/local/libgdgd.so
Then restart the php service. If it doesn’t work, try reboot

Okay, but one last reminder, you must know that there are many surprises in this world. When installing source code and only adding the gd library, the PHP version and library version are different

, so:
- There is no guarantee that there will be rewards after paying so much
- There is no guarantee that gd.so will be successfully loaded
- No guarantee against pregnancy

So if it is a source code installation, it is best to add the parameter --with-gd when compiling PHP

GD library functions

GetImageSize
Function: Get the size of the image [i.e. length and width] Usage: array GetImageSize(string filename, array [imageinfo]);

ImageArc
Function: draw arc Usage: int ImageArc(int im, int cx, int cy, int w, int h, int s, int e, int col);

ImageChar
Function: write horizontal characters Usage: int ImageChar(int im, int font, int x, int y, string c, int col);

ImageCharUp
Function: Write vertical characters Usage: int ImageCharup(int im, int font, int x, int y, string c, int col);

ImageColorAllocate
Function: Match colors Usage: int ImageColorAllocate(int im, int red, int green, int blue);

ImageColorTransparent
Function: Specify transparent background color Usage: int ImageColorTransparent(int im, int [col]);

ImageCopyResized
Function: Copy a new image and resize Usage: int ImageCopyResized(int dst_im, int src_im, int dstX, int dstY, int srcX,

int srcY, int dstW, int dstH, int srcW, int srcH);

ImageCreate
Function: Create a new image Usage: int ImageCreate(int x_size, int y_size);

ImageDashedLine
Function: Draw a dotted line Usage: int ImageDashedLine(int im, int x1, int y1, int x2, int y2, int col);
ImageDestroy Function: End graphics Usage explanation: int ImageDestroy(int im);

ImageFill
Function: Graphic coloring Usage: int ImageFill(int im, int x, int y, int col);

ImageFilledPolygon function: polygon area coloring Usage: int ImageFilledPolygon(int im, array points, int num_points,

int col);

ImageFilledRectangle function: rectangular area coloring Usage: int ImageFilledRectangle(int im, int x1, int y1, int x2, int

y2, int col);

ImageFillToBorder function: coloring within the specified color area Usage: int ImageFillToBorder(int im, int x, int y, int border,

int col);

ImageFontHeight
Function: Get the height of the font Usage: int ImageFontHeight(int font);

ImageFontWidth function: Get the width of the font Usage: int ImageFontWidth(int font);

ImageInterlace function: use interlaced display or not Usage: int ImageInterlace(int im, int [interlace]);

ImageLine function: draw solid line Usage: int ImageLine(int im, int x1, int y1, int x2, int y2, int col);

ImageLoadFont Function: Load bitmap font Usage: int ImageLoadFont(string file);

ImagePolygon function: draw polygons Usage: int ImagePolygon(int im, array points, int num_points, int col);

ImageRectangle function: draw rectangle Usage: int ImageRectangle(int im, int x1, int y1, int x2, int y2, int col);

ImageSetPixel function: draw points Usage: int ImageSetPixel(int im, int x, int y, int col); ImageString function: draw horizontal

String Usage: int ImageString(int im, int font, int x, int y, string s, int col);

ImageStringUp function: draw straight string Usage: int ImageStringUp(int im, int font, int x, int y, string s, int

col);

ImageSX
Function: Get the width of the image Usage: int ImageSX(int im);

ImageSY
Function: Get the height of the image Usage: int ImageSY(int im);

ImageTTFBBox
Function: Calculate the area occupied by TTF text Usage: array ImageTTFBBox(int ​​size, int angle, string fontfile, string text);

ImageTTFText function: write TTF text into the image Usage: array ImageTTFText(int im, int size, int angle, int x, int y,

int col, string fontfile, string text); ImageColorAt Function: Get the index value of the color of the specified point in the image Usage: int

ImageColorAt(int im, int x, int y);

ImageColorClosest
Function: Calculate the closest color to the specified color in the color table. Usage: int ImageColorClosest(int im, int red, int green, int blue);

ImageColorExact
Function: Calculate the specified color index value on the color table Usage: int ImageColorExact(int im, int red, int green, int blue);

ImageColorResolve
Function: Calculate the index value of the specified or closest color on the color table. Usage: int ImageColorResolve(int im, int red, int green, int

blue);

ImageColorSet
Function: Set the color of the specified index on the color table. Usage: boolean ImageColorSet(int im, int index, int red, int green, int

blue); ImageColorsForIndex Function: Get the color of the specified index on the color table Usage: array ImageColorsForIndex(int ​​im, int

index);

ImageColorsTotal
Function: Calculate the color number of the graph Usage: int ImageColorsTotal(int im); ImagePSLoadFont Function: Load PostScript font Usage

：int ImagePSLoadFont(string filename);

ImagePSFreeFont
Function: Remove PostScript font Usage: void ImagePSFreeFont(int fontindex);

ImagePSEncodeFont
Function: Convert PostScript font to vector font Usage: int ImagePSEncodeFont(string encodingfile);

ImagePSText function: write PostScript text into the image Usage: array ImagePSText(int image, string text, int font, int

size, int foreground, int background, int x, int y, int space, int tightness, float angle, int

antialias_steps);

ImagePSBBox function: Calculate the area occupied by PostScript text Usage: array ImagePSBBox(string text, int font, int size,

int space, int width, float angle);

ImageCreateFromPNG Function: Take out PNG graphics Usage: int ImageCreateFromPng(string filename);

ImagePNG function: Create PNG graphics Usage: int ImagePng(int im, string [filename]);

ImageCreateFromGIF Function: Remove GIF graphics Usage: int ImageCreateFromGif(string filename);

ImageGIF function: Create GIF graphics Usage: int ImageGif(int im, string [filename]);

http://www.bkjia.com/PHPjc/628710.htmlwww.bkjia.comtruehttp: //www.bkjia.com/PHPjc/628710.htmlTechArticleOpening the GD library is an important parameter in php. It is commonly used to process images. Any processing of images requires GD. Library support, below I will introduce the methods and commands to open the GD library in various systems, big...