shell_exec，imagemagick将pdf转换为jpg返回错误

Question

I use imagemagick convert PDF file to JPG , use PHP shell_exec('convert ./a.pdf ./a.jpg')

I get this error:

Error: /undefined in findresource Operand stack: --dict:15/24(L)-- F3 16.0 --dict:6/6(L)-- --dict:6/6(L)-- DroidSansFallback-UniGB-UTF16-H --dict:10/12(ro)(G)-- --nostringval-- CIDFontObject --dict:7/7(L)-- --dict:7/7(L)-- Adobe-GB1 Execution stack: %interp_exit .runexec2 --nostringval-- --nostringval-- --nostringval-- 2 %stopped_push --nostringval-- --nostringval-- --nostringval-- false 1 %stopped_push 1862 1 3 %oparray_pop 1861 1 3 %oparray_pop 1845 1 3 %oparray_pop --nostringval-- --nostringval-- 2 1 1 --nostringval-- %for_pos_int_continue --nostringval-- --nostringval-- --nostringval-- --nostringval-- %array_continue --nostringval-- false 1 %stopped_push --nostringval-- %loop_continue --nostringval-- --nostringval-- --nostringval-- --nostringval-- --nostringval-- --nostringval-- %array_continue --nostringval-- --nostringval-- --nostringval-- --nostringval-- --nostringval-- %loop_continue Dictionary stack: --dict:1154/1684(ro)(G)-- --dict:1/20(G)-- --dict:75/200(L)-- --dict:75/200(L)-- --dict:106/127(ro)(G)-- --dict:286/300(ro)(G)-- --dict:22/25(L)-- --dict:4/6(L)-- --dict:26/40(L)-- Current allocation mode is local Last OS error: 2

Command in console is ok.

Answer 1

The answer is almost certainly related to the PATH - either to convert or ghostscript (which is required for the PDF aspect).

Try the following, which doesn't require ghostscript:

shell_exec('convert a.jp b.jpg');

If that works, it's the PATH to ghostscript that is wrong.

If it doesn't work, it is the PATH to convert which is wrong, or the script is not getting executed in the folder you think it is.

As you state in the comments, the following actually solves the problem:

putenv("PATH=/usr/local/bin");